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split higgsinos are a compelling class of models to explain dark matter and may be on the verge of detection by multiple current experimental avenues. the idea is based on a large split in scales between the electroweak scale and decoupled scalars, with relatively light higgsinos between the two. such models enjoy the merit of depending on very few parameters while still explaining gauge coupling unification, dark matter, and most of the hierarchy between the planck and electroweak scales, and they remain undetected by past experiments. we analyze split higgsinos in view of current and next generation experiments. we discuss the direct and indirect detection prospects and further demonstrate promising discovery potentials in the upcoming electron electric dipole moment experiments. the parameter space of this model is analyzed in terms of experiments expected to run in the coming years and where we should be looking for the next potential discoveries. | race to find split higgsino dark matter |
new fundamental particles at the mass scale of a few tev c-2 could account for observed phenomena that cannot be explained by the standard model (sm) of particle physics, including the microscopic origin of dark matter and the macroscopic imbalance of matter over antimatter in the universe. however, no beyond-the-sm (bsm) particles at the tev scale have yet been detected at the large hadron collider (lhc). with recent innovations, searches for time-reversal symmetry (t) violation through low-energy precision measurements of electric dipole moments (edms) of atoms and molecules have attained the sensitivity to detect indirect signatures of certain particles with masses of more than 10 tev c-2. in this perspective, we discuss recent developments in the measurement and interpretation of edms, and assess proposed techniques for future experiments that could push experimental limits on t-violating bsm physics to the pev scale. | atoms and molecules in the search for time-reversal symmetry violation |
in the simplest higgs-portal scalar dark matter model, the dark matter mass has been restricted to be either near the resonant mass (mh / 2) or in a large-mass region by the direct detection at lhc run 1 and lux. while the large-mass region below roughly 3 tev can be probed by the future xenon1t experiment, most of the resonant mass region is beyond the scope of xenon1t. in this paper, we study the direct detection of such scalar dark matter in the narrow resonant mass region at the 14 tev lhc and the future 100 tev hadron collider. we show the luminosities required for the 2σ exclusion and 5σ discovery. | collider signatures of higgs-portal scalar dark matter |
we propose new ideas to directly search for light dark matter, such as the axion or the dark photon, by using magnetometry with nitrogen-vacancy centers in diamonds. if the dark matter couples to the electron spin, it affects the evolution of the bloch vectors consisting of the spin triplet states, which may be detected through several magnetometry techniques. we give several concrete examples with the use of dc and ac magnetometry and estimate the sensitivity on dark matter couplings. | light dark matter search with nitrogen-vacancy centers in diamonds |
the present work investigates the possibility that both dark matter and the anomalous magnetic moment of the muon may be explained within the context of the inverse seesaw extended next-to-minimal supersymmetric standard model (iss-nmssm). in iss-nmssm, the newly introduced higgs-neutrino yukawa coupling yν provides additional higgsino-sneutrino loop contribution to (g -2 )μ. if the deviation between the experimental observations and the standard model predictions of the anomalous muon magnetic moment is confirmed by the further experimental and theoretical studies, it can be explained naturally within the iss-nmssm framework without conflicting with the current stringent limits on the direct detection of dark matter and large hadron collider searches. | anomalous muon magnetic moment in the inverse seesaw extended next-to-minimal supersymmetric standard model |
we study dark matter (dm) phenomenology with multiple dm species consisting of both scalar and vector dm particles. more specifically, we study the hidden gauged su(3) model of arcadi et al. before proceeding to the hidden gauged su(3) model, we study the relic abundances of simplified multispecies dm scenarios to gain some insights when multiple species and interactions are included. in the hidden gauged su(3) model, because of the large parameter space, we restrict ourselves to three representative benchmark points, each with multiple dm species. the relic densities for the benchmark points were found using a program developed to solve the coupled boltzmann equations for an arbitrary number of interacting dm species with two particles in the final state. for each case, we varied the mass of the dm particles and then found the value of the dark su(3) gauge coupling that gives the correct relic density. we found that for some sets of parameter values dm would be difficult to observe in direct detection experiments but would be easier to observe in indirect detection experiments while for other sets of parameter values the situation was reversed so that measurements from both types of experiments complement each other and could help pinpoint the details of the hidden su(3) model. important to this is that, even for moderate changes in input parameter values, the relative relic density of each species can change significantly, resulting in large changes in the observability of multispecies dm by direct or indirect detection. | multicomponent dark matter from a hidden gauged su(3) |
direct detection for sub-gev dark matter is developing rapidly, with many novel experimental ideas and theoretical methods emerging. in this work, we extend the dielectric formalism for dark matter scattering to incorporate anisotropic material responses, enabling directionally sensitive experiments with a broad class of target materials. using a simple model of an anisotropic electron gas, we demonstrate the importance of many-body effects such as the plasmon and show that, even when the dark matter kinetic energies are much smaller than the plasmon energy, the tail of an anisotropic plasmon can still produce a sizable daily modulation. we highlight the relevant experimental techniques required to establish the target response as well as the challenges in extracting a response function which is truly free of modeling uncertainties. | directional detection of dark matter with anisotropic response functions |
for direct detection of sub-mev dark matter, a promising strategy is to search for individual phonon excitations in a crystal. we perform an analytic calculation of the rate for light dark matter (kev <mdm<mev ) to produce two acoustic phonons through scattering in cubic crystals such as gaas, ge, si, and diamond. the multiphonon rate is always smaller than the rate to produce a single optical phonon, whenever the latter is kinematically accessible. in si and diamond, there is a dark matter mass range for which multiphonon production can be the most promising process, depending on the experimental threshold. | multiphonon excitations from dark matter scattering in crystals |
neutron stars can provide new insight into dark matter properties, as these dense objects capture dark matter particles very efficiently. it has recently been shown that the energy transfer in the dark matter capture process can lead to appreciable heating of neutron stars, which may be observable with forthcoming infra-red telescopes. we examine this heating in the context of inelastic dark matter, for which signals in conventional nuclear-recoil based direct detection experiments are highly suppressed when the momentum transfer is small compared to the mass splitting between dark matter states. neutron stars permit inelastic scattering for much greater mass splittings, because dark matter particles are accelerated to velocities close to the speed of light during infall. using an effective operator approach for fermionic dm that scatters inelastically, we show that the observation of a very cold neutron star would lead to very stringent limits on the interaction strengths that, in most cases, are much stronger than any present, or future, direct detection experiment on earth. this holds both for elastic scattering and for inelastic scattering with mass splittings up to ~ 300mev. | heating up neutron stars with inelastic dark matter |
the earth-stopping effect plays a crucial role in the direct detection of sub-gev dark matter. besides the elastic scattering process, the quasielastic and deep inelastic scatterings between dark matter and nucleus that are usually neglected can dominate the interaction, especially in the accelerated dark matter scenarios, which may affect the dark matter detection sensitivity significantly for the underground experiments. we calculate such inelastic scattering contributions in the earth-stopping effect and illustrate the essence of our argument with the atmospheric dark matter. with the available data, we find that the resulting upper limits on the atmospheric dark matter-nucleus scattering cross section can differ from those only considering the elastic scattering process by about 1 order of magnitude. | accelerated-light-dark-matter-earth inelastic scattering in direct detection |
the migdal effect is attracting interest because of the potential to enhance the sensitivities of direct dark matter searches to the low-mass region. in spite of its great importance, the migdal effect has not been experimentally observed yet. a realistic experimental approach towards the first observation of the migdal effect in the neutron scattering was studied with monte carlo simulations. in this study, the potential background rate was studied together with the event rate of the migdal effect by a neutron source. it was found that a table-top-sized $\sim (30~\mbox{cm})^3$ position-sensitive gaseous detector filled with argon or xenon target gas can detect characteristic signatures of the migdal effect with sufficient rates (o( $10^2\sim10^3$ ) events per day). a simulation result of a simple experimental set-up showed two significant background sources, namely the intrinsic neutrons and the neutron-induced gamma-rays. it is found that the intrinsic neutron background rate for the argon gas is at an acceptable level and some future study of the reduction of the gamma-rays from the laboratory would make the observation of the migdal effect possible. the background for the xenon gas, on the other hand, is found to be much more serious than for the argon gas. future works on the isotope separation as well as the reduction of the gamma-rays from the detector and laboratory will be needed before the migdal effect can be observed for the xenon gas case. | detection capability of the migdal effect for argon and xenon nuclei with position-sensitive gaseous detectors |
the scattering of neutral particles by an atomic nucleus can lead to electronic ionisation and excitation through a process known as the migdal effect. we revisit and improve upon previous calculations of the migdal effect, using the dirac-hartree-fock method to calculate the atomic wavefunctions. our methods do not rely on the use of the dipole approximation, allowing us to present robust results for higher nuclear recoil velocities than was previously possible. our calculations provide the theoretical foundations for future measurements of the migdal effect using neutron sources, and searches for dark matter in direct detection experiments. we show that multiple ionisation must be taken into account in experiments with fast neutrons, and derive the semi-inclusive probability for processes that yield a hard electron above a defined energy threshold. we present results for the noble elements up to and including xenon, as well as carbon, fluorine, silicon and germanium. the transition probabilities from our calculations are publicly available. | precise predictions and new insights for atomic ionisation from the migdal effect |
light dark sectors in thermal contact with the standard model can naturally produce the observed relic dark matter abundance and are the targets of a broad experimental search program. a key light dark sector model is the pseudo-dirac fermion with a dark photon mediator. the dynamics of the fermionic excited states are often neglected. we consider scenarios in which a nontrivial abundance of excited states is produced and their subsequent de-excitation yields interesting electromagnetic signals in direct detection experiments. we study three mechanisms of populating the excited state: a primordial excited fraction, a component up-scattered in the sun, and a component up-scattered in the earth. we find that the fractional abundance of primordial excited states is generically depleted to exponentially small fractions in the early universe. nonetheless, this abundance can produce observable signals in current dark matter searches. mev-scale dark matter with thermal cross sections and higher can be probed by down-scattering following excitation in the sun. up-scatters of gev-scale dark matter in the earth can give rise to signals in current and upcoming terrestrial experiments and x-ray observations. we comment on the possible relevance of these scenarios to the recent excess in xenon1t. | electromagnetic signals of inelastic dark matter scattering |
the annual modulation signal observed by the dama experiment is a long-standing question in the community of dark matter direct detection. this necessitates an independent verification of its existence using the same detection technique. the cosine-100 experiment has been operating with 106 kg of low-background nai(tl) detectors providing interesting checks on the dama signal. however, due to higher backgrounds in the nai(tl) crystals used in cosine-100 relative to those used for dama, it was difficult to reach final conclusions. since the start of cosine-100 data taking in 2016, we also have initiated a program to develop ultra-pure nai(tl) crystals for cosine-200, the next phase of the experiment. the program includes efforts of raw powder purification, ultra-pure nai(tl) crystal growth, and detector assembly techniques. after extensive research and development of nai(tl) crystal growth, we have successfully grown a few small-size (0.61-0.78 kg) thallium-doped crystals with high radio-purity. a high light yield has been achieved by improvements of our detector assembly technique. here we report the ultra-pure nai(tl) detector developments at the institute for basic science, korea. the technique developed here will be applied to the production of nai(tl) detectors for the cosine-200 experiment. | development of ultra-pure nai(tl) detectors for the cosine-200 experiment |
the dark matter interpretation for a recent observation of excessive electron recoil events at the xenon1t detector seems challenging because its velocity is not large enough to give rise to recoiling electrons of o (kev ). fast-moving or boosted dark matter scenarios are receiving attention as a remedy for this issue, rendering the dark matter interpretation a possibility to explain the anomaly. we investigate various scenarios where such dark matter of spin 0 and 1/2 interacts with electrons via an exchange of vector, axial-vector, pseudo-scalar, or scalar mediators. we find parameter values not only to reproduce the excess but to be consistent with existing bounds. our study suggests that the scales of mass and coupling parameters preferred by the excess can be mostly affected by the type of mediator, and that significantly boosted dark matter can explain the excess depending on the mediator type and its mass choice. the method proposed in this work is general, and hence readily applicable to the interpretation of observed data in the dark matter direct detection experiment. | implications of the xenon1t excess on the dark matter interpretation |
in this paper, the electroweak phase transition, the gravitational waves and the dark matter issues are investigated in two scalar singlet extension of the standard model. the detectability of the gravitational wave signals are discussed by comparing the results with the sensitivity curves of elisa, alia, decigo and bbo detectors. it is shown that the results support the recent reports on the dark matter relic density by planck 2018 collaboration and the direct detection experiment by xenon1t 2018 collaboration. | electroweak phase transition, gravitational waves and dark matter in two scalar singlet extension of the standard model |
generically, the effective coupling between the dark matter and an atom scales with the number of constituents in the atom, resulting in the effective coupling being proportional to the mass of the atom. in this limit, when the momentum transfer is also small, we show that the leading term in the scattering of a particle off the optical phonons of an array of atoms, whether in a crystal or in a molecule, vanishes. next-generation dark matter direct detection experiments with sub-electron-volt energy thresholds will operate in a regime where this effect is important, and the suppression can be up to order 1 06 over naive expectations. for dark matter that couples differently to protons and neutrons, the suppression is typically of order 10-100 but can be avoided through a judicious choice of material, utilizing variations in nuclear ratios z /a to break the proportionality of the coupling to mass. we provide explicit illustrations of this effect by calculating structure factors for dimolecules and for the crystals nai and sapphire. | dark matter phonon coupling |
we investigate direct detection signatures of dark matter particles interacting with quarks via a light spin-0 mediator with general cp phases. since tree-level scattering may be strongly suppressed in the non-relativistic limit, loop contributions play an important role and can lead to observable signals in near-future experiments. we study the phenomenology of different mediator masses and cp phases with an emphasis on scenarios with maximal cp violation and higgs portal models. intriguingly, the sum of the rates obtained at tree- and loop-level can give a characteristic recoil spectrum not obtainable from a single type of interaction. we furthermore develop a novel method for decomposing the two-loop contribution to effective interactions between dark matter and gluons into two separate one-loop diagrams, which in our case substantially simplifies the calculation of the important top-quark contribution. | loop-induced direct detection signatures from cp-violating scalar mediators |
dark matter direct detection experiments are designed to look for the scattering of dark matter particles that are assumed to move with virial velocities $\sim 10^{-3}$. at these velocities, the energy deposition in the detector is large enough to cause ionization/scintillation, forming the primary class of signatures looked for in such experiments. these experiments are blind to a large class of dark matter models where the dark matter has relatively large scattering cross-sections with the standard model, resulting in the dark matter undergoing multiple scattering with the atmosphere and the rock overburden, and thus slowing down considerably before arriving at underground detectors. we propose to search for these kinds of dark matter by looking for the anomalous heating of a well shielded and sensitive calorimeter. in this detector concept, the dark matter is thermalized with the rock overburden but is able to pierce through the thermal shields of the detector causing anomalous heating. using the technologies under development for edelweiss and supercdms, we estimate the sensitivity of such a calorimetric detector. in addition to models with large dark matter - standard model interactions, these detectors also have the ability to probe dark photon dark matter. | calorimetric detection of dark matter |
we present converged ab initio calculations of structure factors for elastic spin-dependent wimp scattering off all nuclei used in dark matter direct-detection searches: 19f, 23na, 27al, 29si, 73ge, 127i, and 129xe131. from a set of established two- and three-nucleon interactions derived within chiral effective field theory, we construct consistent wimp-nucleon currents at the one-body level, including effects from axial-vector two-body currents. we then apply the in-medium similarity renormalization group to construct effective valence-space hamiltonians and consistently transformed operators of nuclear responses. combining the recent advances of natural orbitals with three-nucleon forces expressed in large spaces, we obtain basis-space converged structure factors even in heavy nuclei. generally results are consistent with previous calculations but large uncertainties in 127i highlight the need for further study. | ab initio structure factors for spin-dependent dark matter direct detection |
the detection of ultralight dark matter through interactions with nucleons, electrons, and photons has been explored in depth. in this work we propose to use precision muon experiments, specifically muon g-2 and electric dipole moment measurements, to detect ultralight dark matter (dm) that couples predominantly to muons. we set direct, terrestrial limits on dm-muon interactions using existing g-2 data, and show that a time-resolved reanalysis of ongoing and upcoming precession experiments will be sensitive to dark matter signals. intriguingly, we also find that the current muon g-2 anomaly can be explained by a spin torque applied to muons from a pseudoscalar dark matter background that induces an oscillating electric dipole moment for the muon. this explanation may be verified by a time-resolved reanalysis. | muon g-2 and edm experiments as muonic dark matter detectors |
we propose a simple theory for the idea that cosmological dark matter (dm) may be present today mainly in the form of stable neutral hadronic thermal relics. in our model, neutrino masses arise radiatively from the exchange of colored dm constituents, giving a common origin for both dark matter and neutrino mass. the exact conservation of b -l symmetry ensures dark matter stability and the dirac nature of neutrinos. the theory can be falsified by dark matter nuclear recoil direct detection experiments, leading also to possible signals at a next generation hadron collider. | bound-state dark matter and dirac neutrino masses |
we present the first search for a dark matter annual modulation signal in the southern hemisphere conducted with nai(tl) detectors, performed by the dm-ice17 experiment. nuclear recoils from dark matter interactions are expected to yield an annually modulated signal independent of location within the earth's hemispheres. dm-ice17, the first step in the dm-ice experimental program, consists of 17 kg of nai(tl) located at the south pole under 2200 m.w.e. overburden of antarctic glacial ice. taken over 3.6 years for a total exposure of 60.8 kg yr, dm-ice17 data are consistent with no modulation in the energy range of 4-20 kev, providing the strongest limits on weakly interacting massive particle dark matter from a direct detection experiment located in the southern hemisphere. the successful deployment and stable long-term operation of dm-ice17 establishes the south pole ice as a viable location for future dark matter searches and in particular for a high-sensitivity nai(tl) dark matter experiment to directly test the dama/libra claim of the observation of dark matter. | first search for a dark matter annual modulation signal with nai(tl) in the southern hemisphere by dm-ice17 |
superconducting detectors have been proposed as outstanding targets for the direct detection of light dark matter scattering at masses as low as a kev. we study the prospects for directional detection of dark matter in isotropic superconducting targets from the angular distribution of excitations produced in the material. we find that dark matter scattering produces initial excitations with an anisotropic distribution, and further show that this directional information can be preserved as the initial excitations relax. our results demonstrate that directional detection is possible for a wide range of dark matter masses, and pave the way for light dark matter discovery with bulk superconducting targets. | directional detection of light dark matter in superconductors |
new ideas for low-mass dark matter direct detection suggest that narrow band gap materials, such as dirac semiconductors, are sensitive to the absorption of mev dark matter or the scattering of kev dark matter. here we propose spin-orbit semiconductors—materials whose band gap arises due to spin-orbit coupling—as low-mass dark matter targets owing to their o (10 mev) band gaps. we present three material families that are predicted to be spin-orbit semiconductors using density functional theory (dft), assess their electronic and topological features, and evaluate their use as low-mass dark matter targets. in particular, we find that the tin pnictide compounds are especially suitable having a tunable range of mev-scale band gaps with anisotropic fermi velocities allowing directional detection. finally, we address the pitfalls in the dft methods that must be considered in the ab initio prediction of narrow-gapped materials, including those close to the topological critical point. | prediction of tunable spin-orbit gapped materials for dark matter detection |
the dark matter experiment using argon pulse-shape discrimination (deap) has been designed for a direct detection search for particle dark matter using a single-phase liquid argon target. the projected cross section sensitivity for deap-3600 to the spin-independent scattering of weakly interacting massive particles (wimps) on nucleons is 10-46cm2 for a 100 gev/c2 wimp mass with a fiducial exposure of 3 tonne-years. this paper describes the physical properties and construction of the deap-3600 detector. | design and construction of the deap-3600 dark matter detector |
the dama/libra collaboration has reported the observation of an annual modulation in the event rate that has been attributed to dark matter interactions over the last two decades. however, even though tremendous efforts to detect similar dark matter interactions were pursued, no definitive evidence has been observed to corroborate the dama/libra signal. many studies assuming various dark matter models have attempted to reconcile dama/libra's modulation signals and null results from other experiments, however no clear conclusion can be drawn. apart from the dark matter hypothesis, several studies have examined the possibility that the modulation is induced by variations in detector's environment or their specific analysis methods. in particular, a recent study presents a possible cause of the annual modulation from an analysis method adopted by the dama/libra experiment in which the observed annual modulation could be reproduced by a slowly varying time-dependent background. here, we study the cosine-100 data using an analysis method similar to the one adopted by the dama/libra experiment and observe a significant annual modulation, however the modulation phase is almost opposite to that of the dama/libra data. assuming the same background composition for cosine-100 and dama/libra, simulated experiments for the dama/libra without dark matter signals also provide significant annual modulation with an amplitude similar to dama/libra with opposite phase. even though this observation does not directly explain the dama/libra results directly, this interesting phenomenon motivates more profound studies of the time-dependent dama/libra background data. | an induced annual modulation signature in cosine-100 data by dama/libra's analysis method |
direct detection of and lhc search for the singlet fermion dark matter (sfdm) model with higgs portal interaction are considered in a renormalizable model where the full standard model (sm) gauge symmetry is imposed by introducing a singlet scalar messenger. in this model, direct detection is described by an effective operator mq q bar q χ bar χ as usual, but the full amplitude for monojet + e̸t involves two intermediate scalar propagators, which cannot be seen within the effective field theory (eft) or in the simplified model without the full sm gauge symmetry. we derive the collider bounds from the atlas monojet + e̸t as well as the cms t t bar +e̸t data, finding out that the bounds and the interpretation of the results are completely different from those obtained within the eft or simplified models. it is pointed out that it is important to respect unitarity, renormalizability and local gauge invariance of the sm. | beyond the dark matter effective field theory and a simplified model approach at colliders |
atomic nuclei are important laboratories for exploring and testing new insights into the universe, such as experiments to directly detect dark matter or explore properties of neutrinos. the targets of interest are often heavy, complex nuclei that challenge our ability to reliably model them (as well as quantify the uncertainty of those models) with classical computers. hence there is great interest in applying quantum computation to nuclear structure for these applications. as an early step in this direction, especially with regards to the uncertainties in the relevant quantum calculations, we develop circuits to implement variational quantum eigensolver (vqe) algorithms for the lipkin-meshkov-glick model, which is often used in the nuclear physics community as a testbed for many-body methods. we present quantum circuits for vqe for two and three particles and discuss the construction of circuits for more particles. implementing the vqe for a two-particle system on the ibm quantum experience, we identify initialization and two-qubit gates as the largest sources of error. we find that error mitigation procedures reduce the errors in the results significantly, but additional quantum hardware improvements are needed for quantum calculations to be sufficiently accurate to be competitive with the best current classical methods. | lipkin model on a quantum computer |
we present the migdal in galactic dark matter exploration (migdal) experiment aiming at the unambiguous observation and study of the so-called migdal effect induced by fast-neutron scattering. it is hoped that this elusive atomic process can be exploited to enhance the reach of direct dark matter search experiments to lower masses, but it is still lacking experimental confirmation. our goal is to detect the predicted atomic electron emission which is thought to accompany nuclear scattering with low, but calculable, probability, by deploying an optical time projection chamber filled with a low-pressure gas based on cf4. initially, pure cf4 will be used, and then in mixtures containing other elements employed by leading dark matter search technologies - including noble species, plus si and ge. high resolution track images generated by a gas electron multiplier stack, together with timing information from scintillation and ionisation readout, will be used for 3d reconstruction of the characteristic event topology expected for this process - an arrangement of two tracks sharing a common vertex, with one belonging to a migdal electron and the other to a nuclear recoil. different energy-loss rate distributions along both tracks will be used as a powerful discrimination tool against background events. in this article we present the design of the experiment, informed by extensive particle and track simulations and detailed estimations of signal and background rates. in pure cf4 we expect to observe 8.9 (29.3) migdal events per calendar day of exposure to an intense d-d (d-t) neutron generator beam at the nile facility located at the rutherford appleton laboratory (uk). with our nominal assumptions, 5 σ median discovery significance can be achieved in under one day with either generator. | the migdal experiment: measuring a rare atomic process to aid the search for dark matter |
one of the highest priorities in particle physics today is the identification of the constituents of dark matter. this manuscript is a supplement to pedagogical lectures given at the 2021 les houches summer school on dark matter. the lectures cover topics related to the direct detection of wimp dark matter, including the distribution of dark matter, nuclear scattering, backgrounds, planning and designing of experiments and a sampling of planned and ongoing experiments. | dark matter direct detection of classical wimps |
measuring dark matter (dm) signals via electron recoil provides an important means for direct detection of light dm particles. the recent xenon1t anomaly with electron recoil energy around er = (2-3) kev can be naturally explained by dm inelastic scattering which injects energy to the recoiled electrons and gives a narrow peak structure in the recoil spectrum. we present an effective field theory (eft) approach to exothermic inelastic dm signals for the xenon electron recoil detection. for relatively heavy mediator, we fairly formulate the dm-lepton interactions by effective contact operators with two dm fields (x, x') and two leptons. using the xenon1t data, we fit the electron recoil spectrum and constrain the allowed scalar dm mass-splitting as 2.1 kev < δm < 3.3 kev (95% c.l.), with the best fit δm = 2.8 kev . we analyze the relic abundance produced by such effective dm-electron contact interaction. to provide both the dm relic abundance and the xenon1t excess, we derive new constraints on the dm mass and the uv cutoff scale of dm effective interactions. finally, we study possible uv completions for the effective dm-lepton contact interactions. | eft approach of inelastic dark matter for xenon electron recoil detection |
we assess the status of a wide class of wimp dark matter (dm) models in light of the latest experimental results using the global fitting framework gambit. we perform a global analysis of effective field theory (eft) operators describing the interactions between a gauge-singlet dirac fermion and the standard model quarks, the gluons and the photon. in this bottom-up approach, we simultaneously vary the coefficients of 14 such operators up to dimension 7, along with the dm mass, the scale of new physics and several nuisance parameters. our likelihood functions include the latest data from planck, direct and indirect detection experiments, and the lhc. for dm masses below 100 gev, we find that it is impossible to satisfy all constraints simultaneously while maintaining eft validity at lhc energies. for new physics scales around 1 tev, our results are influenced by several small excesses in the lhc data and depend on the prescription that we adopt to ensure eft validity. furthermore, we find large regions of viable parameter space where the eft is valid and the relic density can be reproduced, implying that wimps can still account for the dm of the universe while being consistent with the latest data. | thermal wimps and the scale of new physics: global fits of dirac dark matter effective field theories |
the measurement of an annual modulation in the event rate of direct dark matter detection experiments is a powerful tool for dark matter discovery. indeed, several experiments have already claimed such a discovery in the past decade. while most of them have later revoked their conclusions, and others have found potentially contradictory results, one still stands today. this paper explains the potential as well as the challenges of annual modulation measurements, and gives an overview on past, present and future direct detection experiments. | annual modulation in direct dark matter searches |
in the framework of the mssm, we examine several simplified models where only a few superpartners are light. this allows us to study wimp-nucleus scattering in terms of a handful of mssm parameters and thereby scrutinize their impact on dark matter direct-detection experiments. focusing on spin-independent wimp-nucleon scattering, we derive simplified, analytic expressions for the wilson coefficients associated with higgs and squark exchange. we utilize these results to study the complementarity of constraints due to direct-detection, flavor, and collider experiments. we also identify parameter configurations that produce (almost) vanishing cross sections. in the proximity of these so-called blind spots, we find that the amount of isospin violation may be much larger than typically expected in the mssm. this feature is a generic property of parameter regions where cross sections are suppressed, and highlights the importance of a careful analysis of the nucleon matrix elements and the associated hadronic uncertainties. this becomes especially relevant once the increased sensitivity of future direct-detection experiments corners the mssm into these regions of parameter space. | light stops, blind spots, and isospin violation in the mssm |
the observation of the higgs boson solidified the standard model of particle physics. however, explanations of anomalies (for example, dark matter) rely on further symmetry breaking, calling for an undiscovered axial higgs mode1. the higgs mode was also seen in magnetic, superconducting and charge density wave (cdw) systems2,3. uncovering the vector properties of a low-energy mode is challenging, and requires going beyond typical spectroscopic or scattering techniques. here we discover an axial higgs mode in the cdw system rte3 using the interference of quantum pathways. in rte3 (r = la, gd), the electronic ordering couples bands of equal or different angular momenta4-6. as such, the raman scattering tensor associated with the higgs mode contains both symmetric and antisymmetric components, which are excited via two distinct but degenerate pathways. this leads to constructive or destructive interference of these pathways, depending on the choice of the incident and raman-scattered light polarization. the qualitative behaviour of the raman spectra is well captured by an appropriate tight-binding model, including an axial higgs mode. elucidation of the antisymmetric component is direct evidence that the higgs mode contains an axial vector representation (that is, a pseudo-angular momentum) and hints that the cdw is unconventional. thus, we provide a means for measuring quantum properties of collective modes without resorting to extreme experimental conditions. | axial higgs mode detected by quantum pathway interference in rte3 |
the xenon1t experiment uses a time projection chamber (tpc) with liquid xenon to search for weakly interacting massive particles (wimps), a proposed dark matter particle, via direct detection. as this experiment relies on capturing rare events, the focus is on achieving a high recall of wimp events. hence the ability to distinguish between wimp and the background is extremely important. to accomplish this, we suggest using convolutional neural networks (cnns); a machine learning procedure mainly used in image recognition tasks. to explore this technique we use xenon collaboration open-source software to simulate the tpc graphical output of dark matter signals and main backgrounds. a cnn turns out to be a suitable tool for this purpose, as it can identify features in the images that differentiate the two types of events without the need to manipulate or remove data in order to focus on a particular region of the detector. we find that the cnn can distinguish between the dominant background events (er) and 500 gev wimp events with a recall of 93.4%, precision of 81.2% and an accuracy of 87.2%. | convolutional neural networks for direct detection of dark matter |
the migdal effect has received much attention from the dark matter direct detection community, in particular due to its power in setting leading limits on sub-gev particle dark matter. however, it is crucial to obtain experimental confirmation of the migdal effect through nuclear scattering using standard model probes. in this work, we extend existing calculations of the migdal effect to the case of neutron-nucleus scattering, with a particular focus on neutron scattering angle distributions in silicon. we identify kinematic regimes wherein the assumptions present in current calculations of the migdal effect hold for neutron scattering and demonstrate that these include viable neutron calibration schemes. we then apply this framework to propose an experimental strategy to measure the migdal effect in cryogenic silicon detectors using an upgrade to the nexus facility at fermilab. | measuring the migdal effect in semiconductors for dark matter detection |
dirac fermion dark matter models with heavy z ' mediators are subject to stringent constraints from spin-independent direct searches and from lhc bounds, cornering them to live near the z ' resonance. such constraints can be relaxed, however, by turning off the vector coupling to standard model fermions, thus weakening direct detection bounds, or by resorting to light z ' masses, below the z pole, to escape heavy resonance searches at the lhc. in this work we investigate both cases, as well as the applicability of our findings to majorana dark matter. we derive collider bounds for light z ' gauge bosons using the clsmethod, spin-dependent scattering limits, as well as the spin-independent scattering rate arising from the evolution of couplings between the energy scale of the mediator mass and the nuclear energy scale, and indirect detection limits. we show that such scenarios are still rather constrained by data, and that near resonance they could accommodate the gamma-ray gev excess in the galactic center. | augury of darkness: the low-mass dark z ' portal |
in this work we present a simple extension of the standard model that contains, as the only new physics component, a massive spin-one matter field in the adjoint representation of s u (2 )l. in order to be consistent with perturbative unitarity, the vector field must be odd under a z2 symmetry. radiative corrections make the neutral component of the triplet (v0) slightly lighter than the charged ones. we show that v0 can be the dark matter particle while satisfying all current bounds if it has a mass between 2.8 and 3.8 tev. we present the current limit on the model parameter space from highly complementary experimental constraints, including dark matter relic density measurement, dark matter direct and indirect detection searches, lhc data on higgs couplings to photons and lhc data on disappearing track searches. we also show that the two-dimensional parameter space can be fully covered by disappearing track searches at a future 100 tev hadron collider, which will probe, in particular, the whole mass range relevant for dark matter, thus giving an opportunity to discover or exclude the model. | minimal spin-one isotriplet dark matter |
in this white paper we present and discuss a concrete proposal for the consistent interpretation of dark matter searches at colliders and in direct detection experiments. based on a specific implementation of simplified models of vector and axial-vector mediator exchanges, this proposal demonstrates how the two search strategies can be compared on an equal footing. | interplay and characterization of dark matter searches at colliders and in direct detection experiments |
we analyze data from the dark matter direct detection experiments pandax-4t, lux-zeplin and xenonnt to place bounds on neutrino electromagnetic properties (magnetic moments, millicharges, and charge radii). we also show how these bounds will improve at the future facility darwin. in our analyses we implement a more conservative treatment of background uncertainties than usually done in the literature. from the combined analysis of all three experiments we can place very strong bounds on the neutrino magnetic moments and on the neutrino millicharges. we show that even though the bounds on the neutrino charge radii are not very strong from the analysis of current data, darwin could provide the first measurement of the electron neutrino charge radius, in agreement with the standard model prediction. | testing neutrino electromagnetic properties at current and future dark matter experiments |
we study the structure factors for spin-independent wimp scattering off xenon based on state-of-the-art large-scale shell-model calculations, which are shown to yield a good spectroscopic description of all experimentally relevant isotopes. our results are based on the leading scalar one-body currents only. at this level and for the momentum transfers relevant to direct dark matter detection, the structure factors are in very good agreement with the phenomenological helm form factors used to give experimental limits for wimp-nucleon cross sections. in contrast to spin-dependent wimp scattering, the spin-independent channel, at the one-body level, is less sensitive to nuclear structure details. in addition, we explicitly show that the structure factors for inelastic scattering are suppressed by ∼1 0-4 compared to the coherent elastic scattering response. this implies that the detection of inelastic scattering will be able to discriminate clearly between spin-independent and spin-dependent scattering. finally, we provide fits for all calculated structure factors. | nuclear structure aspects of spin-independent wimp scattering off xenon |
direct detection experiments for light (sub-gev) dark matter are making enormous leaps in reaching previously unexplored theory space. the need for accurate characterizations of target responses has led to a growing interplay between particle and condensed matter physics. this white paper summarizes recent progress on direct detection calculations that utilize state-of-the-art numerical tools in condensed matter physics and effective field theory techniques. these new results provide the theoretical framework for interpreting ongoing and planned experiments using electronic and collective excitations, and for optimizing future searches. | snowmass white paper: light dark matter direct detection at the interface with condensed matter physics |
due to the low nuclear recoils, sub-gev dark matter (dm) is usually beyond the sensitivity of the conventional dm direct detection experiments. the boosted and migdal scattering mechanisms have been proposed as two new complementary avenues to search for light dm. in this study, we consider the momentum-transfer effect in the dm-nucleus scattering to derive the new bounds on sub-gev dm for these two scenarios. we show that such an effect is sizable so that the existing bounds on the dm-nucleus scattering cross section can be improved significantly. | new strong bounds on sub-gev dark matter from boosted and migdal effects |
we consider loop level contributions to dark matter— nucleon scattering in cases where the spin independent scattering cross section is absent or suppressed at tree level. in the case of a pseudoscalar interaction, for which the tree level cross section is both spin-dependent and suppressed by 4 powers of the exchanged momentum, loop diagrams give rise to a non-zero spin independent cross section. we show that if the pseudoscalar interaction is formulated using a gauge invariant framework, loop effects generate an effective bar chiχ h vertex and result in a scattering cross section that is within reach of current or forthcoming experiments. we also consider the case of inelastic dark matter, for which the dominant interaction terms have an off diagonal χ1-χ2 structure. in this case, the tree-level direct detection cross section is negligible when the inelastic χ1 n → χ2 n process is kinematically suppressed. however, loop diagrams generate a diagonal χ1-χ1 interaction and hence permit measurable, spin independent, χ1 n → χ1 n elastic scattering. as such, we are able to probe parameter space that was previously considered inaccessible to direct detection. | loop effects in direct detection |
we explore the relic density of dark matter and the particle spectrum within a constrained version of an e6 inspired susy model with an extra u(1)n gauge symmetry. in this model a single exact custodial symmetry forbids tree-level flavor-changing transitions and the most dangerous baryon and lepton number violating operators. we present a set of benchmark points showing scenarios that have a sm-like higgs mass of 125 gev and sparticle masses above the lhc limits. they lead to striking new physics signatures which may be observed during run ii of the lhc and can distinguish this model from the simplest susy extensions of the sm. at the same time these benchmark scenarios are consistent with the measured dark matter abundance and necessarily lead to large dark matter direct detection cross sections close to current limits and observable soon at the xenon1t experiment. | e6 inspired susy benchmarks, dark matter relic density and a 125 gev higgs |
in this paper, we minimize and compare two different fine-tuning measures in four high-scale supersymmetric models that are embedded in the mssm. in addition, we determine the impact of current and future dark matter direct detection and collider experiments on the fine-tuning. we then compare the low-scale electroweak measure with the high-scale barbieri-giudice measure. we find that they reduce to the same value when the higgsino parameter drives the degree of fine-tuning. we also find spectra where the high-scale measure turns out to be lower than the low-scale measure. depending on the high-scale model and fine-tuning definition, we find a minimal fine-tuning of 3-38 (corresponding to o(10-1)%) for the low-scale measure, and 63-571 (corresponding to o(1-0.1)%) for the high-scale measure. we stress that it is too early to conclude on the fate of supersymmetry, based only on the fine-tuning paradigm. | the current status of fine-tuning in supersymmetry |
conventional dark matter direct detection experiments set stringent constraints on dark matter by looking for elastic scattering events between dark matter particles and nuclei in underground detectors. however these constraints weaken significantly in the sub-gev mass region, simply because light dark matter does not have enough energy to trigger detectors regardless of the dark matter-nucleon scattering cross section. even if future experiments lower their energy thresholds, they will still be blind to parameter space where dark matter particles interact with nuclei strongly enough that they lose enough energy and become unable to cause a signal above the experimental threshold by the time they reach the underground detector. therefore in case dark matter is in the sub-gev region and strongly interacting, possible underground scatterings of dark matter with terrestrial nuclei must be taken into account because they affect significantly the recoil spectra and event rates, regardless of whether the experiment probes dm via dm-nucleus or dm-electron interaction. to quantify this effect we present the publicly available dark matter simulation code for underground scatterings (damascus), a monte carlo simulator of dm trajectories through the earth taking underground scatterings into account. our simulation allows the precise calculation of the density and velocity distribution of dark matter at any detector of given depth and location on earth. the simulation can also provide the accurate recoil spectrum in underground detectors as well as the phase and amplitude of the diurnal modulation caused by this shadowing effect of the earth, ultimately relating the modulations expected in different detectors, which is important to decisively conclude if a diurnal modulation is due to dark matter or an irrelevant background. | damascus: the impact of underground scatterings on direct detection of light dark matter |
the large underground xenon (lux) dark matter experiment aims to detect rare low-energy interactions from weakly interacting massive particles (wimps). the radiogenic backgrounds in the lux detector have been measured and compared with monte carlo simulation. measurements of lux high-energy data have provided direct constraints on all background sources contributing to the background model. the expected background rate from the background model for the 85.3 day wimp search run is (2.6 ±0.2stat ±0.4sys) ×10-3 events kevee-1 kg-1day-1 in a 118 kg fiducial volume. the observed background rate is (3.6 ±0.4stat) ×10-3 events kevee-1 kg-1day-1 , consistent with model projections. the expectation for the radiogenic background in a subsequent one-year run is presented. | radiogenic and muon-induced backgrounds in the lux dark matter detector |
next generation direct dark matter detection experiments are favorable facilities to probe neutrino properties and light mediators beyond the standard model. we explore the implications of the recent data reported by lux-zeplin (lz) and xenonnt collaborations on electromagnetic neutrino interactions and neutrino generalized interactions (ngis). we show that xenonnt places the most stringent upper limits on the effective and transition neutrino magnetic moment (of the order of few ×10-12μb) as well as stringent constraints to neutrino millicharge (of the order of ∼10-13 e)-competitive to lz-and improved by about one order of magnitude in comparison to existing constraints coming from borexino and texono. we furthermore explore the xenonnt and lz sensitivities to simplified models with light ngis and find improved constraints in comparison to those extracted from borexino-phase ii data. | implications of first lz and xenonnt results: a comparative study of neutrino properties and light mediators |
the korea invisible mass search (kims) collaboration has developed low-background nai(tl) crystals that are suitable for the direct detection of wimp dark matter. building on experience accumulated during the kims-csi programs, the kims-nai experiment will consist of a 200 kg nai(tl) crystal array surrounded by layers of shielding structures and will be operated at the yangyang underground laboratory. the goal is to provide an unambiguous test of the dama/libra annual modulation signature. measurements of six prototype crystals show progress in the reduction of internal contamination from radioisotopes. based on our understanding of these measurements, we expect to achieve a background level in the final detector configuration that is less than 1 count/day/kev/kg for recoil energies around 2 kev. the annual modulation sensitivity for the kims-nai experiment shows that an unambiguous 7σ test of the dama/libra signature would be possible with a 600 kg year exposure with this system. | understanding internal backgrounds in nai(tl) crystals toward a 200 kg array for the kims-nai experiment |
over the next decade new μ →e conversion searches at fermilab (mu2e) and j-parc (comet, deeme) are expected to advance limits on charged lepton flavor violation (clfv) by more than four orders of magnitude. by considering the consequence of p and c p on elastic μ →e conversion and the structure of possible charge and current densities, we show that rates are governed by six nuclear responses and a single scale, q /mn , where q ≈mμ is the momentum transferred from the leptons to the nucleus. to relate this result to microscopic formulations of clfv, we construct in nonrelativistic effective theory (nret) the clfv nucleon-level interaction, pointing out the relevance of the dimensionless scales y =(q/b2 ) 2>| v⃗n|>| v⃗μ|>| v⃗t| , where b is the nuclear size, v⃗n and v⃗μ are the nucleon and muon intrinsic velocities, and v⃗t is the target recoil velocity. we discuss previous work, noting the lack of a systematic treatment of the various small parameters. because the parameter y is not small, a proper calculation of μ →e conversion requires a full multipole expansion of the nuclear response functions, an apparently daunting task with coulomb-distorted electron partial waves. we demonstrate that the multipole expansion can be carried out to high precision by introducing a simplifying local momentum qeff for the electron. previous work has been limited to simple charge or spin interactions, thereby treating the nucleus effectively as a point particle. we show that such formulations are not compatible with the general form of the μ →e conversion rate, failing to generate three of the six allowed nuclear response functions. the inclusion of the nucleon velocity v⃗n yields an nret with 16 operators and a rate of the general form. consequently, in the current discovery era for clfv, it provides the most sensible starting point for experimental analysis, defining what can and cannot be determined about clfv from the highly exclusive process of μ →e conversion. finally, we expand the nret operator basis to account for the effects of v⃗μ, associated with the muon's lower component, generating corrections to the clfv coefficients of the point-nucleus response functions. using advanced shell-model methods, we compute μ →e conversion rates for a series of experimental targets, deriving bounds on the coefficients of the clfv operators. these calculations are the first to include a general basis of clfv operators, full evaluation of the associated nuclear response functions, and an accurate treatment of electron and muon coulomb effects. we discuss target selection as an experimental "knob" that can be turned to probe the microscopic origins of clfv. we describe two types of coherence that enhance certain clfv operators and selection rules that blind elastic μ →e conversion to others. we discuss the matching of the nret onto higher level effective field theories, such as those constructed at the light quark level, noting opportunities to build on existing work in direct detection of dark matter. we discuss the relation of μ →e conversion to μ →e +γ and μ →3 e , showing how meg ii and mu3e results will complement those of mu2e and comet. finally we describe a accompanying script—in mathematica and python versions—that can be used to compute μ →e conversion rates in various nuclear targets for the full set of nret operators. | nuclear-level effective theory of μ →e conversion: formalism and applications |
we discuss the singlet-doublet fermion dark matter model with c p -violation. in this model, the c p violation generates a pseudoscalar interaction of dark matter with the standard model-higgs boson. thanks to the pseudoscalar interaction, the model can evade the strong constraint from the dark matter direct detection experiments while keeping the success of the thermal relic scenario. the c p violation also predicts signals in dark matter indirect detection experiments and electric dipole moments (edm) that can be as large as the current upper bound. we investigate the constraints and prospects of the direct detection experiments, the indirect detection experiment, and the electron edm. we also investigate the stability of the higgs potential. combining these observables, we find that heavy dark matter is disfavored. we also find it is possible to probe the higgs funnel region by the combination of the direct detection experiments and the measurements of the electron edm if experiments for the electron edm reach to o (10-32) e cm in future. | current status and future prospects of the singlet-doublet dark matter model with c p violation |
various types of electroweak-interacting particles, which have non-trivial charges under the su(2) l× u(1) ygauge symmetry, appear in various extensions of the standard model. these particles are good targets of future lepton colliders, such as the international linear collider (ilc), the compact linear collider (clic) and the future circular collider of electrons and positrons (fcc-ee). an advantage of the experiments is that, even if their beam energies are below the threshold of the production of the new particles, quantum effects of the particles can be detected through high precision measurements. we estimate the capability of future lepton colliders to probe electroweak-interacting particles through the quantum effects, with particular focus on the wino, the higgsino and the so-called minimal dark matters, and found that a particle whose mass is greater than the beam energy by 100-1000 gev is detectable by measuring di-fermion production cross sections with o(0.1)% accuracy. in addition, with the use of the same analysis, we also discuss the sensitivity of the future colliders to model independent higher dimensional operators, and found that the cutoff scales corresponding to the operators can be probed up to a few ten tev. | indirect probe of electroweak-interacting particles at future lepton colliders |
direct detection experiments search for the interactions of dark matter (dm) particles with nuclei in terrestrial detectors. but if these interactions are sufficiently strong, dm particles may scatter in the earth, affecting their distribution in the lab. we present a new analytic calculation of this `earth-scattering' effect in the regime where dm particles scatter at most once before reaching the detector. we perform the calculation self-consistently, taking into account not only those particles which are scattered away from the detector, but also those particles which are deflected towards the detector. taking into account a realistic model of the earth and allowing for a range of dm-nucleon interactions, we present the earthshadow code, which we make publicly available, for calculating the dm velocity distribution after earth-scattering. focusing on low-mass dm, we find that earth-scattering reduces the direct detection rate at certain detector locations while increasing the rate in others. the earth's rotation induces a daily modulation in the rate, which we find to be highly sensitive to the detector latitude and to the form of the dm-nucleon interaction. these distinctive signatures would allow us to unambiguously detect dm and perhaps even identify its interactions in regions of the parameter space within the reach of current and future experiments. | signatures of earth-scattering in the direct detection of dark matter |
we calculate the leading radiative corrections to the dark-matter-nucleon scattering in the pseudo-nambu-goldstone dark matter model augmented with a second higgs doublet (s2hdm). in this model, the cross sections for the scattering of the dark-matter on nuclei vanishes at tree-level in the limit of zero momentum-transfer due to a u(1) symmetry. however, this symmetry is softly broken in order to give a mass to the dark-matter particle. as a consequence, non-vanishing scattering cross sections arise at the loop level. we find that the current cross-section limits from dark-matter direct-detection experiments can hardly constrain the parameter space of the s2hdm. however, the loop-corrected predictions for the scattering cross sections can be well within the reach of future direct-detection experiments. as a consequence, future phenomenological analyses of the s2hdm should take into account cross-section predictions beyond tree-level and the experimental constraints from dark-matter direct-detection experiments. | direct detection of pseudo-nambu-goldstone dark matter in a two higgs doublet plus singlet extension of the sm |
given the fact that the relatively light higgsino mass μ favored in natural supersymmetry usually results in a sizable scattering cross section between the neutralino dark matter and the nucleon, we study the impact of the recently updated direct detection bounds from lux experiment, including both spin independent (si) and spin dependent (sd) measurements, on the parameter space of natural next-to-minimal supersymmetric standard model (nnmssm). different from the common impression that the si bound is stronger than the sd one, we find that the sd bound is complementary to the si bound and in some cases much more powerful than the latter in limiting the nnmssm scenarios. after considering the lux results, nnmssm is severely limited, e.g. for the peculiar scenarios of the nmssm where the next-to-lightest cp-even higgs corresponds to the 125gev higgs boson discovered at the lhc, the samples obtained in our random scan are excluded by more than 85%. by contrast, the monojet search at the lhc run-i can not exclude any sample of nnmssm. we also investigate the current status of nnmssm and conclude that, although the parameter points with low fine tuning are still attainable, they are distributed in some isolated parameter islands which are difficult to get. future dark matter direct search experiments such as xenon-1t will provide a better test of nnmssm. | strong constraints of lux-2016 results on the natural nmssm |
the annual modulation of scintillation event rate observed by the dama/libra experiment has been a long-standing controversy in the quest of the direct detection of dark matter. the effort to definitively confirm or refute the annual modulation has turned out to be challenging due to the lack of nai(tl) crystals with high enough radiopurity. most recently, we successfully grew a 6-kg ingot free from contamination during growth, from which a 3.4-kg crystal scintillator was made. the 39k concentration in the final crystal is estimated to be 4.3 ±0.2 ppb , unprecedented for nai(tl) crystals. the 210pb activity is estimated to be 0.34 ±0.04 mbq /kg via α counting of 210po, among the lowest of currently running nai-based dark matter experiments except dama/libra. more importantly, the techniques and protocols we have developed will further contribute to the growth of ultra-high purity nai(tl) crystals for dark matter searches. | growth of ultra-high purity nai(tl) crystals for dark matter searches |
we propose a new extension of the standard model by a $u(1)_{b-l}$ gauge symmetry in which the anomalies are canceled by two right-handed neutrinos plus four chiral fermions with fractional b-l charges. two scalar fields that break the b-l symmetry and give masses to the new fermions are also required. after symmetry breaking, two neutrinos acquire majorana masses via the seesaw mechanism leaving a massless neutrino in the spectrum. additionally, the other new fermions arrange themselves into two dirac particles, both of which are automatically stable and contribute to the observed dark matter density. this model thus realizes in a natural way, without ad hoc discrete symmetries, a two-component dark matter scenario. we analyze in some detail the dark matter phenomenology of this model. the dependence of the relic densities with the parameters of the model is illustrated and the regions consistent with the observed dark matter abundance are identified. finally, we impose the current limits from lhc and direct detection experiments, and show that the high mass region of this model remains unconstrained. | two-component dark matter and a massless neutrino in a new b-l model |
fermion dark matter (dm) interacting with the standard model through a higgs portal requires non-renormalizable operators, signaling the presence of new mediator states at the electroweak scale. collider signatures that involve the mediators are a powerful tool to experimentally probe the higgs portal interactions, providing complementary information to strong constraints set by direct dm detection searches. indirect detection experiments are less sensitive to this scenario. we investigate the collider reach for the mediators using three minimal renormalizable models as examples, and requiring the fermion dm to be a thermal relic. the large hadron collider in its high-energy, high-luminosity phase can probe most scenarios if dm is lighter than about 200 gev. beyond this scale, future high-energy experiments such as an electron-positron collider or a 100-tev proton-proton collider, combined with future direct detection experiments, are indispensable to conclusively test these models. | integrating in the higgs portal to fermion dark matter |
we present a detailed study of a combined singlet-doublet scalar and singlet-doublet fermion model for dark matter. these models have only been studied separately in the past. we show that their combination allows for the radiative generation of neutrino masses, but that it also implies the existence of lepton-flavour violating (lfv) processes. we first analyse the dark matter, neutrino mass and lfv aspects separately. we then perform two random scans for scalar dark matter imposing higgs mass, relic density and neutrino mass constraints, one over the full parameter space, the other over regions where scalar-fermion coannihilations become important. in the first case, a large part of the new parameter space is excluded by lfv, and the remaining models will be probed by xenonnt. in the second case, direct detection cross sections are generally too small, but a substantial part of the viable models will be tested by future lfv experiments. possible constraints from the lhc are also discussed. | a singlet doublet dark matter model with radiative neutrino masses |
in this work we numerically re-examine the loop-induced wimp-nucleon scattering cross section for the simplified dark matter models and the constraint set by the latest direct detection experiment. we consider a fermion, scalar or vector dark matter component from five simplified models with leptophobic spin-0 mediators coupled only to standard model quarks and dark matter particles. the tree-level wimp-nucleon cross sections in these models are all momentum-suppressed. we calculate the non-suppressed spin-independent wimp-nucleon cross sections from loop diagrams and investigate the constrained space of dark matter mass and mediator mass by xenon1t. the constraints from indirect detection and collider search are also discussed. | revisiting the direct detection of dark matter in simplified models |
till today, the nature of dark matter (dm) remains elusive despite all our efforts. this missing matter of the universe has not been observed by the already operating dm direct-detection experiments, but we can infer its gravitational effects. galaxies and clusters of galaxies are most likely to contain dm trapped to their gravitational field. this leads us to the natural assumption that compact objects might contain dm too. among the compact objects exist in galaxies, neutron stars considered as natural laboratories, where theories can be tested, and observational data can be received. thus, many models of dm they have proposed it's presence in those stars. by employing the two fluid model, we discovered a stable area in the m-r diagram of a celestial formation consisting of neutron and dm that is substantial in size and vast in dimensions. this formation spans hundreds of kilometers in diameter and possesses a mass equivalent to 100 or more times that of our sun. to elucidate, this entity resembles an enormous celestial body of dm, with a neutron star at its core. this implies that a supramassive stellar compact entity can exist without encountering any issues of stability and without undergoing a collapse into a black hole. in any case, the present theoretical prediction can, if combined with corresponding observations, shed light on the existence of dm and even more on its basic properties. | supramassive dark objects with neutron star origin |
we study the light right-handed slepton bulk regions for dark matter from the generalized minimal supergravity (gmsugra) in the minimal supersymmetric standard model (mssm). in our comprehensive numerical studies, we show that $\mathcal{r_{\tilde{\phi}}}\gtrsim10\%$ is a conservative criteria to formulate bulk region, where $\mathcal{r_{\tilde{\phi}}}\equiv({m_{\tilde{\phi}}-m_{\tilde{\chi}_1^0}})/{m_{\tilde{\chi}_1^0}}$. for right-handed stau as the next to the lightest supersymmetric partcile (nlsp), we find a large viable parameter space, consistent with the current lhc constraints, planck2018 dark matter relic density bounds, and direct bounds on neutralino-nucleons scattering cross-section that naturally supports the right-handed stau bulk regions for dark matter. in particular, the upper bounds on the masses of the lightest supersymmetric particle (lsp) neutralino and right-handed stau are about 120.4 gev and 138 gev, respectively. this bulk region may be beyond the current lhc reach and could be probed at lux-zeplin, a next-generation dark matter direct detection experiment, the future circular collider (fcc-ee) at cern, and the circular electron positron collider (cepc). however, the scenario with the right-handed selectron as the nlsp is excluded by the lhc supersymmetry searches. | the right-handed slepton bulk regions for dark matter in the generalized minimal supergravity (gmsugra) |
we propose the optomechanical dark-matter instrument (odin), based on a new method for the direct detection of low-mass dark matter. we consider dark matter interacting with superfluid helium in an optomechanical cavity. using an effective field theory, we calculate the rate at which dark matter scatters off phonons in a highly populated, driven acoustic mode of the cavity. this scattering process deposits a phonon into a second acoustic mode in its ground state. the deposited phonon ($\mu$ev range) is then converted to a photon (ev range) via an optomechanical interaction with a pump laser. this photon can be efficiently detected, providing a means to sensitively probe kev scale dark matter. we provide realistic estimates of the backgrounds and discuss the technical challenges associated with such an experiment. we calculate projected limits on dark matter-nucleon interactions for dark matter masses ranging from 0.5 to 300 kev and estimate that a future device could probe cross-sections as low as $\mathcal{o}(10^{-32})$ cm$^2$. | optomechanical dark matter direct detection |
predictivity of many non-thermal dark matter (dm) models is marred by the gravitational production background. this problem is ameliorated in models with lower reheating temperature $t_r$, which allows for dilution of gravitationally produced relics. we study the freeze-in dark matter production mechanism in the thermal bath with the electroweak scale temperature. the process is boltzmann-suppressed if the dark matter mass is above $t_r$. in this case, the coupling to the thermal bath has to be significant to account for the observed dark matter relic density. as a result, the direct dm detection experiments already probe such freeze-in models, excluding significant parts of parameter space. the forthcoming experiments will explore this framework further, extending to lower couplings and higher reheating temperatures. | freeze-in at stronger coupling |
the new experiments with spheres-gas (news-g) collaboration intends to achieve sub-gev/c2 weakly interacting massive particles (wimps) detection using spherical proportional counters (spcs). spcs are gaseous detectors relying on ionisation with a single ionization electron energy threshold. the latest generation of spc for direct dark matter searches has been installed at snolab in canada in 2021. this article details the different processes involved in the fabrication of the news-g experiment. also outlined in this paper are the mitigation strategies, measurements of radioactivity of the different components, and estimations of induced background event rates that were used to quantify and address detector backgrounds. | the news-g detector at snolab |
the absence of a breakthrough in directly observing dark matter (dm) through prominent large-scale detectors motivates the development of novel tabletop experiments probing more exotic regions of the parameter space. if dm contains ultralight bosonic particles, they would behave as a classical wave and could manifest through an oscillating force on baryonic matter that is coherent over $\sim 10^6$ periods. our helium ultralight dark matter optomechanical sensor (helios) uses the high-$q$ acoustic modes of superfluid helium-4 to resonantly amplify this signal. a superconducting re-entrant microwave cavity enables sensitive optomechanical readout ultimately limited by thermal motion at millikelvin temperatures. pressurizing the helium allows for the unique possibility of tuning the mechanical frequency to effectively broaden the dm detection bandwidth. we demonstrate the working principle of our prototype helios detector and show that future generations of helios could explore unconstrained parameter space for both scalar and vector ultralight dm after just an hour of integration time. | helios: the superfluid helium ultralight dark matter detector |
we investigate, for the first time, a scenario where the dark matter consists of three complex scalar fields that are stabilized by a single z7 symmetry. as an extension of the well-known scalar higgs-portal, this z7 model is also subject to important restrictions arising from the relic density constraint and from direct detection experiments. our goal in this paper is to find and characterize the viable regions of this model, and to analyze its detection prospects in future experiments. first, the processes that affect the relic densities are identified (they include semiannihilations and conversions) and then incorporated into the boltzmann equations for the dark matter abundances, which are numerically solved with micromegas. by means of random scans of the parameter space, the regions consistent with current data, including the recent direct detection limit from the lz experiment, are selected. our results reveal that the z7 model is indeed viable over a wide range of dark matter masses and that both conversions and semiannihilations play an important role in determining the relic densities. remarkably, we find that in many cases all three of the dark matter particles give rise to observable signals in future direct detection experiments, providing a suitable way to test this scenario. | the z7 model of three-component scalar dark matter |
the classic bogoliubov theory of weakly interacting bose gases rests upon the assumption that nearly all the bosons condense into the lowest quantum state at sufficiently low temperatures. here we develop a generalized version of bogoliubov theory for the case of a driven-dissipative exciton-polariton condensate with a large incoherent uncondensed component, or excitonic reservoir. we argue that such a reservoir can consist of both excitonic high-momentum polaritons and optically dark superpositions of excitons across different optically active layers, such as multiple quantum wells in a microcavity. in particular, we predict interconversion between the dark and bright (light-coupled) excitonic states that can lead to a dynamical equilibrium between the condensate and reservoir populations. we show that the presence of the reservoir fundamentally modifies both the energy and the amplitudes of the bogoliubov quasiparticle excitations due to the non-galilean-invariant nature of polaritons. our theoretical findings are supported by our experiment, where we directly detect the bogoliubov excitation branches of an optically trapped polariton condensate in the high-density regime. by analyzing the measured occupations of the excitation branches, we extract the bogoliubov amplitudes across a range of momenta and show that they agree with our generalized theory. | bogoliubov excitations of a polariton condensate in dynamical equilibrium with an incoherent reservoir |
we study a simplified model of top-flavoured dark matter in the framework of dark minimal flavour violation. in this setup the coupling of the dark matter flavour triplet to right-handed up-type quarks constitutes the only new source of flavour and cp violation. the parameter space of the model is restricted by lhc searches with missing energy final states, by neutral d meson mixing data, by the observed dark matter relic abundance, and by the absence of signal in direct detection experiments. we consider all of these constraints in turn, studying their implications for the allowed parameter space. imposing the mass limits and coupling benchmarks from collider searches, we then conduct a combined analysis of all the other constraints, revealing their non-trivial interplay. especially interesting is the combination of direct detection and relic abundance constraints, having a severe impact on the structure of the dark matter coupling matrix. we point out that future bounds from upcoming direct detection experiments, such as xenon1t, xenonnt, lux-zeplin, and darwin, will exclude a large part of the parameter space and push the dm mass to higher values. | top-flavoured dark matter in dark minimal flavour violation |
we discuss an interesting class of models, based on strongly coupled dark matter (dm), where sizable effects can be expected in lhc missing energy (met) searches, compatibly with a large separation of scales. in this case, an effective field theory (eft) is appropriate (and sometimes necessary) to describe the most relevant interactions at the lhc. the selection rules implied by the structure of the new strong dynamics shape the eft in an unusual way, revealing the importance of higher-derivative interactions previously ignored. we compare indications from relic density and direct detection experiments with consistent lhc constraints, and asses the relative importance of the latter. our analysis provides an interesting and well-motivated scenario to model met at the lhc in terms of a handful of parameters. | the last gasp of dark matter effective theory |
the fields of cavity quantum electrodynamics and magnetism have recently merged into cavity spintronics, investigating a quasiparticle that emerges from the strong coupling between standing electromagnetic waves confined in a microwave cavity resonator and the quanta of spin waves, magnons. this phenomenon is now expected to be employed in a variety of devices for applications ranging from quantum communication to dark matter detection. to be successful, most of these applications require a vast control of the coupling strength, resulting in intensive efforts to understanding coupling by a variety of different approaches. here, the electromagnetic properties of both resonator and magnetic samples are investigated to provide a comprehensive understanding of the coupling between these two systems. because the coupling is a consequence of the excitation vector fields, which directly interact with magnetization dynamics, a highly accurate electromagnetic perturbation theory is employed that predicts the resonant hybrid mode frequencies for any field configuration within the cavity resonator. the coupling is shown to be strongly dependent not only on the excitation vector fields and sample's magnetic properties but also on the sample's shape. these findings are illustrated by applying the theoretical framework to two distinct experiments: a magnetic sphere placed in a three-dimensional resonator and a rectangular, magnetic prism placed in a two-dimensional resonator. the theory provides comprehensive understanding of the overall behavior of strongly coupled systems and it can be easily modified for a variety of other systems. | electromagnetic approach to cavity spintronics |
displaced vertices are relatively unusual signatures for dark matter searches at the lhc. we revisit the model of pseudo-dirac dark matter (pddm), which can accommodate the correct relic density, evade direct detection constraints, and generically provide observable collider signatures in the form of displaced vertices. we use this model as a benchmark to illustrate the general techniques involved in the analysis, the complementarity between monojet and displaced vertex searches, and provide a comprehensive study of the current bounds and prospective reach. | displaced vertices from pseudo-dirac dark matter |
a near-future detection of the 21-cm signal from the epoch of reionization will provide unique opportunities to probe the underlying cosmology, provided that such cosmological information can be extracted with precision. to this end, we further develop effective field theory (eft) inspired techniques for the 21-cm brightness temperature field during the epoch of reionization, incorporating renormalized bias and a treatment of redshift space distortions. notably, we confirm that in redshift space, measures of the 21-cm brightness, e.g., the power spectrum, should have irreducible contributions that lack a bias coefficient and therefore contain direct, astrophysics-free information about the cosmological density field; in this work, we study this effect beyond linear order. to validate our theoretical treatment, we fit the predicted eft fourier-space shapes to the thesan suite of hydrodynamical simulations of reionization at the field level, where the considerable number of modes prevents overfitting. we find agreement at the level of a few percent between the 21-cm power spectrum from the eft fits and simulations over the wave number range k ≲0.8 h /mpc and neutral fraction xhi≳0.4 , which is imminently measurable by the hydrogen epoch of reionization array and future experiments. the ability of the eft to describe the 21-cm signal extends to simulations that have different astrophysical prescriptions for reionization as well as simulations with interacting dark matter. | effective bias expansion for 21-cm cosmology in redshift space |
we study a renormalizable scalar singlet dark matter model based on z4 lepton flavor symmetry. a μ τ -philic scalar doublet is introduced as a mediator which connects dark matter and standard model particles. the observed relic abundance of the dark matter is easily maintained while satisfying the current severe constraints on the dark matter from various experiments and observations thanks to the flavor off-diagonal interactions of scalar mediators. we further explore the possibility of dark matter direct detection through the one-loop process. we also find that the relic abundance of the dark matter and the discrepancy of the muon anomalous magnetic moment can be explained by the μ τ -philic scalar mediator simultaneously. | scalar dark matter with a μ τ flavored mediator |
three main strategies are being pursued to search for nongravitational dark matter signals: direct detection, indirect detection and collider searches. interestingly, experiments have reached sensitivities in these three search strategies which may allow detection in the near future. in order to take full benefit of the wealth of experimental data, and in order to confirm a possible dark matter signal, it is necessary to specify the nature of the dark matter particle and of the mediator to the standard model. in this paper, we focus on a simplified model where the dark matter particle is a majorana fermion that couples to a light standard model fermion via a yukawa coupling with a scalar mediator. we review the observational signatures of this model and we discuss the complementarity among the various search strategies, with emphasis in the well motivated scenario where the dark matter particles are produced in the early universe via thermal freeze-out. | signatures of majorana dark matter with t-channel mediators |
we propose a new extension of the standard model by a u (1 )b-l gauge symmetry in which the anomalies are canceled by two right-handed neutrinos plus four chiral fermions with fractional b -l charges. two scalar fields that break the b -l symmetry and give masses to the new fermions are also required. after symmetry breaking, two neutrinos acquire majorana masses via the seesaw mechanism leaving a massless neutrino in the spectrum. additionally, the other new fermions arrange themselves into two dirac particles, both of which are automatically stable and contribute to the observed dark matter density. this model thus realizes in a natural way, without ad hoc discrete symmetries, a two-component dark matter scenario. we analyze in some detail the dark matter phenomenology of this model. the dependence of the relic densities with the parameters of the model is illustrated, and the regions consistent with the observed dark matter abundance are identified. finally, we impose the current limits from lhc and direct detection experiments and show that the high mass region of this model remains unconstrained. | two-component dark matter and a massless neutrino in a new b -l model |
the lack of observation of supersymmetry thus far implies that the weak supersymmetry scale is larger than what was thought before the lhc era. this observation is strengthened by the higgs boson mass measurement at ∼125 gev , which within supersymmetric models implies a large loop correction and a weak supersymmetry scale lying in the several tev region. in addition if neutralino is the dark matter, its relic density puts further constraints on models often requiring coannihilation to reduce the neutralino relic density to be consistent with experimental observation. the coannihilation in turn implies that the mass gap between the lightest supersymmetric particle and the next to lightest supersymmetric particle will be small, leading to softer final states and making the observation of supersymmetry challenging. in this work we investigate stau coannihilation models within supergravity grand unified models and the potential of discovery of such models at the lhc in the post-higgs boson discovery era. we utilize a variety of signal regions to optimize the discovery of supersymmetry in the stau coannihilation region. in the analysis presented we impose the relic density constraint as well as the constraint of the higgs boson mass. the range of sparticle masses discoverable up to the optimal integrated luminosity of the hl-lhc is investigated. it is found that the mass difference between the stau and the neutralino does not exceed ∼20 gev over the entire mass range of the models explored. thus the discovery of a supersymmetric signal arising from the stau coannihilation region will also provide a measurement of the neutralino mass. the direct detection of neutralino dark matter is analyzed within the class of stau coannihilation models investigated. the analysis is extended to include multiparticle coannihilation where stau along with chargino and the second neutralino enter into the coannihilation process. | stau coannihilation, compressed spectrum, and susy discovery potential at the lhc |
we consider a simple abelian vector dark matter (dm) model, where only the dm (x̃μ) couples non-minimally to the scalar curvature (r̃) of the background spacetime via an operator of the form ~x̃μ x̃μ r̃. by considering the standard freeze-out scenario, we show, it is possible to probe such a non-minimally coupled dm in direct detection experiments for a coupling strength ξ~𝒪(1030) and dm mass m x ≲ 55 tev, satisfying planck observed relic abundance and perturbative unitarity. we also discuss dm production via freeze-in, governed by the non-minimal coupling, that requires ξ ≲10-5 to produce the observed dm abundance over a large range of dm mass depending on the choice of the reheating temperature. we further show, even in the absence of the non-minimal coupling, it is possible to produce the whole observed dm abundance via 2-to-2 scattering of the bath particles mediated by massless gravitons. | non-minimally coupled vector boson dark matter |
the dense environment of neutron stars makes them an excellent target for probing dark matter interactions with the standard model. we study neutron star heating from capture of inelastic dark matter, which can evade direct detection constraints. we investigate kinematics of the inelastic scattering process between quasirelativistic dark matter particles and ultrarelativistic targets in neutron stars, and derive analytical expressions for the maximal mass gap allowed for the scattering to occur. we implement them into a fully relativistic formalism for calculating the capture rate and apply it to various scenarios of inelastic dark matter. the projected constraints from neutron stars can systematically surpass those from terrestrial searches, including direct detection and collider experiments. neutron stars can also be sensitive to the parameter space of inelastic self-interacting dark matter. our results indicate that extreme astrophysical environments, such as neutron stars, are an important target for searching dark matter. | heating neutron stars with inelastic dark matter and relativistic targets |
with the goal of generating the galactic center gamma-ray excess, we revisit models in which the dark matter interacts with the standard model through the exchange of a new neutral gauge boson, z' . we find several scenarios that can account for this signal, while respecting all existing constraints from colliders and direct-detection experiments. in such models, the z' either 1) couples axially to light quarks and is leptophobic, 2) couples dominantly to the third generation, or 3) is near resonance, mz'≈2 mdm . we identify an example of an anomaly-free u(1 ) ' that leads to an axial and leptophobic z'. many of the models presented here are within the reach of near-future direct-detection experiments, such as lux and xenon1t. | z' mediated dark matter models for the galactic center gamma-ray excess |
the light yield of a small undoped cesium iodide (csi) crystal directly coupled with two silicon photomultipliers (sipms) at about 77 kelvin was measured to be 43.0 ±1.1 photoelectrons (pe) per kev electron-equivalent (kevee) using x and γ -ray peaks from an 241am radioactive source from 18 to 60 kev. the high light yield together with some other technical advantages illustrate the great potential of this novel combination for neutrino and low-mass dark matter detection, particularly at accelerator-based neutrino sources, where random background can be highly suppressed by requiring coincident triggers between sipms and beam pulse timing signals. some potential drawbacks of using cryogenic sipms instead of photomultiplier tubes (pmts) were identified, such as worse energy resolution and optical cross-talks between sipms. their influence to rare-event detection was discussed and possible solutions were provided. | first operation of undoped csi directly coupled with sipms at 77 k |
traditional dark matter models, e.g., weakly interacting massive particles (wimps), assume dark matter (dm) is weakly coupled to the standard model so that elastic scattering between dark matter and baryons can be described perturbatively by the born approximation; most direct detection experiments are analyzed according to that assumption. we show that when the fundamental dm-baryon interaction is attractive, dark matter-nucleus scattering is nonperturbative in much of the relevant parameter range. the cross section exhibits rich resonant behavior with a highly nontrivial dependence on atomic mass; furthermore, the extended rather than pointlike nature of nuclei significantly impacts the cross sections and must therefore be properly taken into account. the repulsive case also shows significant departures from perturbative predictions and also requires full numerical calculation. these nonperturbative effects change the boundaries of exclusion regions from existing direct detection, astrophysical and cmb constraints. near a resonance value of the parameters the typical velocity-independent yukawa behavior, σ ∼v0, does not apply. we take the nontrivial velocity dependence into account in our analysis, however it turns out that this more accurate treatment has little impact on limits given current constraints. correctly treating the extended size of the nucleus and doing an exact integration of the schrödinger equation does have a major impact relative to past analyses based on the born approximation and naive form factors, so those improvements are essential for interpreting observational constraints. we report the corrected exclusion regions superseding previous limits from xqc, cresst surface run, cmb power spectrum and extensions with lyman-α and milky way satellites, and milky way gas clouds. some limits become weaker, by an order of magnitude or more, than previous bounds in the literature which were based on perturbation theory and pointlike sources, while others become stronger. gaps which open by correct treatment of some particular constraint can sometimes be closed using a different constraint. we also discuss the dependence on mediator mass and give approximate expressions for the velocity dependence near a resonance. sexaquark (u u d d s s ) dm with mass around 2 gev, which exchanges qcd mesons with baryons, remains unconstrained for most of the parameter space of interest. a statement in the literature that a dm-nucleus cross section larger than 10-25 cm2 implies dark matter is composite, is corrected. | resonant scattering between dark matter and baryons: revised direct detection and cmb limits |
an ongoing challenge in dark matter direct detection is to improve the sensitivity to light dark matter in the mev--gev mass range. one proposal is to dope a liquid noble-element direct detection experiment with a lighter element such as hydrogen. this has the advantage of enabling larger recoil energies compared to scattering on a heavy target, while leveraging existing detector technologies. direct detection experiments can also extend their reach to lower masses by exploiting the migdal effect, where a nuclear recoil leads to electronic ionisation or excitation. in this work we combine these ideas to study the sensitivity of a hydrogen-doped lz experiment (hydrox), and a future large-scale experiment such as xlzd. we find that hydrox could have sensitivity to dark matter masses as low as 5~mev for both spin-independent and spin-dependent scattering, with xlzd extending that reach to lower cross sections. notably, this technique substantially enhances the sensitivity of direct detection to spin-dependent proton scattering, well beyond the reach of any current experiments. | exploring light dark matter with the migdal effect in hydrogen-doped liquid xenon |
we propose a new table-top experimental configuration for the direct detection of dark matter qcd axions in the traditional open mass window 10-6 ev ≲ma≲10-2 ev using nonperturbative effects in a system with nontrivial spatial topology. different from most experimental setups found in literature on direct dark matter axion detection, which relies on θ ˙ or ∇ → θ , we found that our system is in principle sensitive to a static θ ≥10-14 and can also be used to set limit on the fundamental constant θqed which becomes the fundamental observable parameter of the maxwell system if some conditions are met. furthermore, the proposed experiments can probe entire open mass window 10-6 ev ≲ma≲10-2 ev with the same design, which should be contrasted with conventional cavity-type experiments being sensitive to a specific axion mass. connection with witten effect when the induced electric charge e' is proportional to θ and the magnetic monopole becomes the dyon with nonvanishing e'=-e θ/2 π is also discussed. | axion detection via topological casimir effect |
pandax-4t is a ton-scale dark matter direct detection experiment using a dual-phase tpc technique at the china jinping underground laboratory. various ultra-low background technologies have been developed and applied to material screening for pandax-4t, including hpge gamma spectroscopy, icp-ms, naa, radon emanation measurement system, krypton assay station, and alpha detection system. low background materials were selected to assemble the detector. surface treatment procedures were investigated to further suppress radioactive background. combining measured results and monte carlo simulation, the total material background rates of pandax-4t in the energy region of 1-25 kev$\rm{}_{ee}$ are estimated to be (9.9 $\pm$ 1.9) $\times \ 10^{-3}$ mdru for electron recoil and (2.8 $\pm$ 0.6) $\times \ 10^{-4}$ mdru for nuclear recoil. in addition, $^{nat}$kr in the detector is estimated to be <8 ppt. | low radioactive material screening and background control for the pandax-4t experiment |
we perform a likelihood analysis of the constraints from accelerator experiments and astrophysical observations on supersymmetric (susy) models with su(5) boundary conditions on soft susy-breaking parameters at the gut scale. the parameter space of the models studied has seven parameters: a universal gaugino mass m_{1/2}, distinct masses for the scalar partners of matter fermions in five- and ten-dimensional representations of su(5), m_5 and m_{10}, and for the 5 and {bar{5}} higgs representations m_{h_u} and m_{h_d}, a universal trilinear soft susy-breaking parameter a_0, and the ratio of higgs vevs tan β . in addition to previous constraints from direct sparticle searches, low-energy and flavour observables, we incorporate constraints based on preliminary results from 13 tev lhc searches for jets + [inlineequation not available: see fulltext.] events and long-lived particles, as well as the latest pandax-ii and lux searches for direct dark matter detection. in addition to previously identified mechanisms for bringing the supersymmetric relic density into the range allowed by cosmology, we identify a novel {tilde{u}_r}/{tilde{c}_r} - tilde{χ }01 coannihilation mechanism that appears in the supersymmetric su(5) gut model and discuss the role of {{tilde{ν }}_τ } coannihilation. we find complementarity between the prospects for direct dark matter detection and susy searches at the lhc. | likelihood analysis of supersymmetric su(5) guts |
scalar dark matter (dm) in a theory introduces hierarchy problems, and suffers from the inability to predict the preferred mass range for the dm. in a wimp-like minimal scalar dm setup we show that the infinite derivative theory can predict the dm mass and its coupling. the scale of nonlocality (m) in such a theory in its lowermost limit (constrained by lhc) implies a dm mass ∼ tev and a coupling with the standard model (sm) higgs λhs ∼ 10-2. planned dm direct detection experiments reaching such sensitivity in the dm will effectively translate into lower bounds on the scale at which the nonlocality comes into the play. | scalar dark matter probes the scale of nonlocality |
we consider direct detection prospects for a class of simplified models of fermionic dark matter (dm) coupled to left and right-handed standard model fermions via two charged scalar mediators with arbitrary mixing angle α. dm interactions with the nucleus are mediated by higher electromagnetic moments, which, for majorana dm, is the anapole moment. after giving a full analytic calculation of the anapole moment, including its α dependence, and matching with limits in the literature, we compute the dm-nucleon scattering cross-section and show the lux and future lz constraints on the parameter space of these models. we then compare these results with constraints coming from f ermi-lat continuum and line searches. results in the supersymmetric limit of these simplified models are provided in all cases. we find that future direct detection experiments will be able to probe most of the parameter space of these models for o (100 - 200) gev dm and lightest mediator mass ≲ o (5%) larger than the dm mass. the direct detection prospects dwindle for larger dm mass and larger mass gap between the dm and the lightest mediator mass, although appreciable regions are still probed for o (200) gev dm and lightest mediator mass ≲ o (20%) larger than the dm mass. the direct detection bounds are also attenuated near certain "blind spots" in the parameter space, where the anapole moment is severely suppressed due to cancellation of different terms. we carefully study these blind spots and the associated f ermi-lat signals in these regions. | simplified dark matter models with charged mediators: prospects for direct detection |
we introduce the fully-depleted charge-coupled device (ccd) as a particle detector. we demonstrate its low energy threshold operation, capable of detecting ionizing energy depositions in a single pixel down to 50 evee. we present results of energy calibrations from 0.3 kevee to 60 kevee, showing that the ccd is a fully active detector with uniform energy response throughout the silicon target, good resolution (fano ∼0.16), and remarkable linear response to electron energy depositions. we show the capability of the ccd to localize the depth of particle interactions within the silicon target. we discuss the mode of operation and unique imaging capabilities of the ccd, and how they may be exploited to characterize and suppress backgrounds. we present the first results from the deployment of 250 μm thick ccds in snolab, a prototype for the upcoming damic100. damic100 will have a target mass of 0.1 kg and should be able to directly test the cdms-si signal within a year of operation. | damic at snolab |
elastic collisions with relativistic electrons from the blazar's jet can accelerate dark matter (dm) particles in the dm spike surrounding the supermassive black hole at its center. this can allow one to set stringent limits on the dm-electron scattering cross section (σ̅eχ ) for dm masses less than 100 mev. we consider dm particles boosted by energetic electrons in the jets of the blazars txs 0506+056 and bl lacertae. both vector and scalar mediators for the scattering of electron and electrophilic fermionic dm are studied. we highlight that the ensuing energy dependence of the s-matrix for the corresponding lorentz structure of the vertex significantly modifies the constraints. we find that the revised exclusion limits are orders of magnitude stronger than the equivalent results for the simple constant cross section assumption. our limits are also assessed for the less cuspy spike. | blazar boosted dark matter - direct detection constraints on σeχ : role of energy dependent cross sections |
open quantum systems with chiral interactions can be realized by coupling atoms to guided radiation modes in photonic waveguides or optical fibers. in their steady state these systems can feature intricate many-body phases such as entangled dark states, but their detection and characterization remains a challenge. here we show how such collective phenomena can be uncovered through monitoring the record of photons emitted into the guided modes. this permits the identification of dark entangled states but furthermore offers novel capabilities for probing complex dynamical behavior, such as the coexistence of a dark entangled and a mixed phase. our results are of direct relevance for current optical experiments, as they provide a framework for probing, characterizing and classifying classical and quantum dynamical features of chiral light–matter systems. | dynamical creation and detection of entangled many-body states in a chiral atom chain |
cosine-100 is a dark matter direct detection experiment designed to test the annual modulation signal observed by the dama/libra experiment. cosine-100 consists of 8 nai(tl) crystals with a total mass of 106 kg, a 2200 l liquid scintillator veto, and 37 muon detector panels. we present details of the data acquisition system of cosine-100, including waveform storage using flash analog-to-digital converters for crystal events and integrated charge storage using charge-sensitive analog-to-digital converters for liquid scintillator and plastic scintillator muon veto events. we also discuss several trigger conditions developed in order to distinguish signal events from photomultiplier noise events. the total trigger rate observed for the crystal/liquid scintillator (plastic scintillator) detector is 15 hz (24 hz). | the cosine-100 data acquisition system |
we explore the implications of third family (t -b -τ ) quasi-yukawa unification (qyu) for collider and dark matter (dm) searches within the framework of a supersymmetric s u (4 )c×s u (2 )l×s u (2 )r model. the deviation from exact yukawa unification is quantified through the relation yt∶yb∶yτ=(1 +c )∶(1 -c )∶(1 +3 c ) , with c being a real parameter (|c |≤0.2 ). we allow for the breaking of left-right symmetry both by the soft scalar and gaugino mass parameters and obtain a variety of viable solutions that predict the sparticle mass spectrum including the lightest supersymmetric particle (lsp) dm (whose stability is guaranteed by a z2 gauge symmetry). we highlight solutions that include a next to lsp (nlsp) gluino with mass ∼1.3 - 2.5 tev , which should be accessible at lhc run 3. there also exist nslp stop solutions with masses heavier than about 1.8 tev, which are consistent with the lsp neutralino dark matter relic density through stop-neutralino coannihilation. we identify a-resonance solutions, which arise when the c p -odd higgs boson is in resonance with a pair of lsp neutralinos (ma=2 mχ∼10) with dm mass ∼0.8 - 2 tev , as well as bino-chargino, bino-slepton and bino-stau coannihilation scenarios. finally, we also identify wino-like (∼99 %) and higgsino-like (∼99 %) solutions whose masses are heavier than about 1.5 and 1 tev, respectively. these solutions are compatible with the desired dark matter relic density and testable in ongoing and future direct detection experiments. | third family quasi-yukawa unification: higgsino dark matter, nlsp gluino, and all that |
light scalar fields, with double well potentials and direct matter couplings, undergo density driven phase transitions, leading to the formation of domain walls. such theories could explain dark energy, dark matter or source the nanohz gravitational-wave background. we describe an experiment that could be used to detect such domain walls in a laboratory experiment, solving for the scalar field profile, and showing how the domain wall affects the motion of a test particle. we find that, in currently unconstrained regions of parameter space, the domain walls leave detectable signatures. | detecting dark domain walls |
we propose a pseudo-goldstone boson dark matter (pgdm) particle in s o (10 ) grand unified theory (gut). due to its goldstone nature, this pgdm evades the direct dm detection experiments which, otherwise, severely constrain the parameter space of dm models. in s o (10 ), the pgdm is embedded as a linear combination of the standard model (sm) singlet scalars in 16h and 126¯ h representations. we consider two scenarios for the intermediate route of s o (10 ) symmetry breaking (sb) to the sm: s u (5 )×u (1 )x and pati-salam the s u (4 )c×s u (2 )l×s u (2 )r (4 -2 -2 ) gauge groups. the vacuum expectation value of 126¯ h , which triggers the breaking of u (1 )x and 4 -2 -2 symmetry in the two scenarios, respectively, determines the pgdm lifetime whose astrophysical lower bound provides one of the most stringent constraints. for the 4 -2 -2 route to s o (10 ), the successful sm gauge coupling unification requires the 4 -2 -2 breaking scale to be o (1011) gev , and most of the parameter space is excluded. for the s u (5 )×u (1 )x route, on the other hand, the u (1 )x breaking scale can be significantly higher, and a wide range of the parameter space is allowed. furthermore, the proton lifetime in the s u (5 ) case is predicted to be 4.53 ×1034 years , which lies well within the sensitivity reach of the hyper-kamiokande experiment. we also examine the constraints on the model parameter space from the large hadron collider and the indirect dm search by fermi-lat and magic experiments. | pseudo-goldstone dark matter in s o (10 ) |
we introduce a systematic approach to characterize the most general nonrelativistic weakly interacting massive particle (wimp)-nucleus interaction allowed by galilean invariance for a wimp of arbitrary spin jχ in the approximation of one-nucleon currents and for a wimp-nucleon effective potential at most linear in the velocity. under these assumptions our framework can be matched to any high-energy model of particle dark matter, including elementary particles and composite states. five nucleon currents arise from the nonrelativistic limit of the free nucleon dirac bilinears. our procedure consists in (1) organizing the wimp currents according to the rank of the 2 jχ+1 irreducible operator products of up to 2 jχ wimp spin vectors, and (2) coupling each of the wimp currents to each of the five nucleon currents. the transferred momentum q appears to a power fixed by rotational invariance. for a wimp of spin jχ we find a basis of 4 +20 jχ independent operators that exhaust all the possible operators that drive elastic wimp-nucleus scattering in the approximation of one-nucleon currents. by comparing our operator basis, which is complete, to the operators already introduced in the literature we show that some of the latter for jχ=1 were not independent and some were missing. we provide explicit formulas for the squared scattering amplitudes in terms of the nuclear response functions, which are available in the literature for most of the targets used in wimp direct detection experiments. | effective theory of nuclear scattering for a wimp of arbitrary spin |
it is well known that for the pure standard model triplet fermionic wimp-type dark matter (dm), the relic density is satisfied around 2 tev. for such a heavy mass particle, the production cross-section at 13 tev run of lhc will be very small. extending the model further with a singlet fermion and a triplet scalar, dm relic density can be satisfied for even much lower masses. the lower mass dm can be copiously produced at lhc and hence the model can be tested at collider. for the present model we have studied the multi jet (≥ 2 j) + missing energy ([inlineequation not available: see fulltext.]) signal and show that this can be detected in the near future of the lhc 13 tev run. we also predict that the present model is testable by the earth based dm direct detection experiments like xenon-1t and in future by darwin. | singlet-triplet fermionic dark matter and lhc phenomenology |
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