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Search for $CP$ violation using $T$-odd correlations in $D^0 \to
K^+K^-π^+π^-$ decays: A search for $CP$ violation using $T$-odd correlations is performed using the
four-body $D^0 \to K^+K^-\pi^+\pi^-$ decay, selected from semileptonic $B$
decays. The data sample corresponds to integrated luminosities of
$1.0\,\text{fb}^{-1}$ and $2.0\,\text{fb}^{-1}$ recorded at the centre-of-mass
energies of 7 TeV and 8 TeV, respectively. The $CP$-violating asymmetry
$a_{CP}^{T\text{-odd}}$ is measured to be $(0.18\pm 0.29\text{(stat)}\pm
0.04\text{(syst)})\%$. Searches for $CP$ violation in different regions of
phase space of the four-body decay, and as a function of the $D^0$ decay time,
are also presented. No significant deviation from the $CP$ conservation
hypothesis is found. | hep |
Search for an invisible $Z^\prime$ in a final state with two muons and
missing energy at Belle II: The $L_{\mu}-L_{\tau}$ extension of the standard model predicts the existence
of a lepton-flavor-universality-violating $Z^{\prime}$ boson that couples only
to the heavier lepton families. We search for such a $Z^\prime$ through its
invisible decay in the process $e^+ e^- \to \mu^+ \mu^- Z^{\prime}$. We use a
sample of electron-positron collisions at a center-of-mass energy of 10.58GeV
collected by the Belle II experiment in 2019-2020, corresponding to an
integrated luminosity of 79.7fb$^{-1}$. We find no excess over the expected
standard-model background. We set 90$\%$-confidence-level upper limits on the
cross section for this process as well as on the coupling of the model, which
ranges from $3 \times 10^{-3}$ at low $Z^{\prime}$ masses to 1 at $Z^{\prime}$
masses of 8$GeV/c^{2}$. | hep |
On Schrödinger superalgebras: We construct, using the supersymplectic framework of Berezin, Kostant and
others, two types of supersymmetric extensions of the Schr\"odinger algebra
(itself a conformal extension of the Galilei algebra). An `$I$-type' extension
exists in any space dimension, and for any pair of integers $N_+$ and $N_-$. It
yields an $N=N_++N_-$ superalgebra, which generalizes the N=1 supersymmetry
Gauntlett et al. found for a free spin-$\half$ particle, as well as the N=2
supersymmetry of the fermionic oscillator found by Beckers et al. In two space
dimensions, new, `exotic' or `$IJ$-type' extensions arise for each pair of
integers $\nu_+$ and $\nu_-$, yielding an $N=2(\nu_++\nu_-)$ superalgebra of
the type discovered recently by Leblanc et al. in non relativistic Chern-Simons
theory. For the magnetic monopole the symmetry reduces to
$\o(3)\times\osp(1/1)$, and for the magnetic vortex it reduces to
$\o(2)\times\osp(1/2)$. | hep |
Unravelling Medium Effects in Heavy Ion Collisions with Zeal: We propose a new observable, called zeal, to analyze events with jets in
heavy ion collisions. The observable measures how a thermal medium affects the
multiplicity and distribution of energetic particles in a jet. Using few known
models for energy loss and jet quenching, we demonstrate its capability to
distinguish the physics of these models. | hep |
Limits on muon-neutrino to tau-neutrino oscillations induced by a
sterile neutrino state obtained by OPERA at the CNGS beam: The OPERA experiment, exposed to the CERN to Gran Sasso $\nu_\mu$ beam,
collected data from 2008 to 2012. Four oscillated $\nu_\tau$ Charged Current
interaction candidates have been detected in appearance mode, which are
consistent with $\nu_\mu \to \nu_\tau$ oscillations at the atmospheric $\Delta
m^2$ within the "standard" three-neutrino framework. In this paper, the OPERA
$\nu_\tau$ appearance results are used to derive limits on the mixing
parameters of a massive sterile neutrino. | hep |
Hadronic decays of B_c mesons with flavor SU(3)_F symmetry: We study implications of a recent observation of non-leptonic $B^+_c\to D^0
K^+$ decay and a bound on $B^+_c\to D^0 \pi^+$ transition on CP-violating
asymmetries in $B_c$ decays. In the U-spin symmetry limit, we derive a relation
between the CP-asymmetries in the $B^+_c\to D^0 K^+$ and $B^+_c\to D^0 \pi^+$
channels and the corresponding branching ratios. We also derive several
relations between non-leptonic $B_c$ decays into the final states with $D$
mesons in the flavor $SU(3)_F$ limit. We point out that a combined study of
$SU(3)_F$ amplitudes in these decays can be used to constrain the angle
$\gamma$ of the Cabibbo-Kobayashi-Maskawa (CKM) matrix. | hep |
Multigrid Monte Carlo with higher cycles in the Sine Gordon model: We study the dynamical critical behavior of multigrid Monte Carlo for the two
dimensional Sine Gordon model on lattices up to 128 x 128. Using piecewise
constant interpolation, we perform a W-cycle (gamma=2). We examine whether one
can reduce critical slowing down caused by decreasing acceptance rates on large
blocks by doing more work on coarser lattices. To this end, we choose a higher
cycle with gamma = 4. The results clearly demonstrate that critical slowing
down is not reduced in either case. | hep |
Vacuum energy and trace anomaly: Concerning the trace anomaly in field theory a nonvanishing vacuum energy
breaks the scale symmetry as well, in addition to the usual beta function
dependent term, requiring a unit operator in the trace anomaly. This additional
term is also necessary in quantum chromodynamics (QCD) to cancel the inherent
ambiguity in the gluon condensate. The inseparability of the gluon condensate
effect from the perturbative contribution to the vacuum energy renders it
impossible to isolate the gluon condensate effect on the cosmological constant. | hep |
Glueballs in Radiative $J/ψ$ Decays: The scalar glueball is observed in a coupled-channel analysis of the $S$-wave
amplitude from BESIII data on radiative $J/\psi$ decays and further data. Ten
scalar isoscalar resonances were required to fit the data. Five of them were
interpreted as mainly-singlet, five as mainly-octet resonances in SU(3). The
yield of resonances showed a striking peak with properties expected from a
scalar glueball. The $D$ wave amplitude in the BESIII data on radiative
$J/\psi$ decays reveales a high-mass structure which can be described by a
single Breit-Wigner or by the sum of three $\phi\phi$ resonances interpreted as
tensor glueballs a long time ago. The structure - and further tensor resonances
observed in radiative $J/\psi$ decays - are tentatively interpreted as tensor
glueball. In $J/\psi$ decays into $\gamma\pi^0\pi^0\eta'$ several resonances
are reported. The possibility is discussed that the pseudoscalar glueball might
be hidden in these data. | hep |
4-d Chern-Simons Theory: Higher Gauge Symmetry and Holographic Aspects: We present and study a 4d Chern-Simons (CS) model whose gauge symmetry is
encoded in a balanced Lie group crossed module. Using the derived formal set-up
recently found, the model can be formulated in a way that in many respects
closely parallels that of the familiar 3d CS one. In spite of these formal
resemblance, the gauge invariance properties of the 4d CS model differ
considerably. The 4d CS action is fully gauge invariant if the underlying base
4fold has no boundary. When it does, the action is gauge variant, the gauge
variation being a boundary term. If certain boundary conditions are imposed on
the gauge fields and gauge transformations, level quantization can then occur.
In the canonical formulation of the theory, it is found that, depending again
on boundary conditions, the 4d CS model is characterized by surface charges
obeying a non trivial Poisson bracket algebra. This is a higher counterpart of
the familiar WZNW current algebra arising in the 3d model. 4d CS theory thus
exhibits rich holographic properties. The covariant Schroedinger quantization
of the 4d CS model is performed. A preliminary analysis of 4d CS edge field
theory is also provided. The toric and Abelian projected models are described
in some detail. | hep |
Influence of intense laser fields on measurable quantities in
$W^{-}$-boson decay: In principle, this paper suggests powerful laser technology as a promising
instrument that can be experimentally useful to control the lifetime and
branching ratio for an unstable particle decay. In a recent paper
[arXiv:2101.00224], we calculated theoretically the $W^{-}$-boson leptonic
decay $(W^{-}\rightarrow \ell^{-} \bar{\nu}_{\ell})$ in the presence of a
circularly polarized laser and we showed that the laser significantly
contributed to the diminution of the leptonic decay rate. In this paper, as a
continuation of the previous one, we mainly deal with the theoretical
calculation of the $W^{-}$-boson hadronic decay $(W^{-}\rightarrow q \bar{q}')$
and we combine the analytical results obtained in both papers to examine the
effect of an intense laser, in terms of its field strength and frequency, on
the three measurable quantities in $W^{-}$-boson decay (total decay rate,
lifetime and branching ratios). It was found that the laser has notably
contributed to the reduction of the total decay rate leading to a longer
lifetime. Most importantly, the two branching ratios (one for leptons and the
other for hadrons) are affected (increased or decreased) by the presence of a
strong external electromagnetic field. Combined together, these two
complementary works may provide an in-depth and comprehensive study that would
be useful for any experimental investigation in the future. | hep |
Solving Renormalization Group Equations by Recursion Relations: Renormalization Group Equations in integro-differential form describing the
evolution of cascades or resumming logarithmic scaling violations have been
known in quantum field theory for a long time. These equations have been
traditionally solved by turning to Mellin moments, since in this space they
become algebraic. x-space solutions are less known, but special asymptotic
expansions exists which allow a fast numerical implementation of these
equations. We illustrate how the equations can be solved using recursion
relations in the next-to-leading order approximation. | hep |
On the effects at colliding mu-meson beams: Possible influence of the weak interaction on the $\mu^+ + \mu^- \to \mu^+ +
\mu^- $ scattering and the $\mu^+ + \mu^- \to e^+ + e^- $ reaction, both
through the neutral lepton currents and the charged ones (in the second order
on weak constant), are considered.
The calculations show that $P$ - odd effects in the mentioned processes would
prove the existence of the neutral currents which, in their turn, give the
principal basis for explanation of the mass difference of a muon and an
electron from the point of view of Ref. [1]. | hep |
Electroweak Symmetry Breaking without the $μ^2$ Term: We demonstrate that from a low energy perspective a viable breaking of the
electroweak symmetry, as present in nature, can be achieved without the
(negative sign) $\mu^2$ mass term in the Higgs potential, thereby avoiding
completely the appearance of relevant operators, featuring coefficients with a
positive mass dimension, in the theory. We show that such a setup is self
consistent and not ruled out by Higgs physics. In particular, we point out that
it is the lightness of the Higgs boson that allows for the electroweak symmetry
to be broken dynamically via operators of $D\geq 4$, consistent with the power
expansion. Beyond that, we entertain how this scenario might even be preferred
phenomenologically compared to the ordinary mechanism of electroweak symmetry
breaking, as realized in the Standard Model, and argue that it can be fully
tested at the LHC. In an appendix, we classify UV completions that could lead
to such a setup, considering also the option of generating all scales
dynamically. | hep |
Systematically Testing Singlet Models for $(g-2)_μ$: We comprehensively study all viable new-physics scenarios that resolve the
muon $(g-2)_\mu$ anomaly with only Standard Model singlet particles coupled to
muons via renormalizable interactions. Since such models are only viable in the
MeV -- TeV mass range and require sizable muon couplings, they predict abundant
accelerator production through the same interaction that resolves the anomaly.
We find that a combination of fixed-target (NA64$\mu$, $M^3$), $B$-factory
(BABAR, Belle II), and collider (LHC, muon collider) searches can cover nearly
all viable singlets scenarios, independently of their decay modes. In
particular, future muon collider searches offer the only certain test of
singlets above the GeV scale, covering all higher masses up to the TeV-scale
unitarity limit for these models. Intriguingly, we find that
$\mathcal{O}(100~\mathrm{GeV})$ muon colliders may yield better coverage for
GeV-scale singlets compared to TeV-scale concepts, which has important
implications for the starting center-of-mass energy of a staged muon collider
program. | hep |
Unparticle Physics in Single Top Signals: We study the single production of top quarks in $e^+e^-, ep$ and $pp$
collisions in the context of unparticle physics through the Flavor Violating
(FV) unparticle vertices and compute the total cross sections for single top
production as functions of scale dimension $d_{\U}$. We find that among all,
LHC is the most promising facility to probe the unparticle physics via single
top quark production processes. | hep |
Dipole factorization for DIS at NLO: Combining the $q\bar{q}$ and
$q\bar{q}g$ contributions: The NLO corrections to the DIS structure functions $F_2$ and $F_L$ (or
equivalently the photon-target cross sections $\sigma^{\gamma^*}_{T}$ and
$\sigma^{\gamma^*}_{L}$) at low $x_{Bj}$ are obtained, as a generalization of
the dipole factorization formula. For the first time, the contributions of both
the $q\bar{q}$ and the $q\bar{q}g$ Fock states in the photon are directly
calculated, using earlier results for the $q\bar{q}$ light-front wave-functions
at one loop inside a dressed virtual photon. Both the $q\bar{q}$ and the
$q\bar{q}g$ contributions have UV divergences, which are shown to cancel each
other, using conventional dimensional regularization as UV regulator. Finally,
the resummation of high-energy logarithms on top of the NLO results for
$\sigma^{\gamma^*}_{T}$ and $\sigma^{\gamma^*}_{L}$ is discussed. | hep |
Schwinger Mechanism for Fermion Pair Production in the Presence of
Arbitrary Time Dependent Background Electric Field: We study the Schwinger mechanism for the pair production of fermions in the
presence of an arbitrary time-dependent background electric field E(t) by
directly evaluating the path integral. We obtain an exact non-perturbative
result for the probability of fermion-antifermion pair production per unit time
per unit volume per unit transverse momentum (of the fermion or antifermion)
from the arbitrary time dependent electric field E(t) via Schwinger mechanism.
We find that the exact non-perturbative result is independent of all the time
derivatives d^nE(t)/dt^n, where n=1,2,....\infty. This result has the same
functional dependence on E as the Schwinger's constant electric field E result
with the replacement: E -> E(t). | hep |
Fitting high-energy Littlest Seesaw parameters using low-energy neutrino
data and leptogenesis: We show that the four high-energy Littlest Seesaw parameters in the flavour
basis,namely two real Yukawa couplings plus the two right-handed neutrino
masses, can be determined by an excellent fit to the seven currently
constrained observables of low-energy neutrino data and leptogenesis. Taking
into account renormalisation group corrections, we estimate $\chi^2 \simeq
1.5-2.6$ for the three d.o.f., depending on the high-energy scale and the type
of non supersymmetric Littlest Seesaw model. We extract allowed ranges of
neutrino parameters from our fit data, including the approximate mu-tau
symmetric predictions $\theta_{23}=45^o\pm 1^o$ and $\delta = -90^o \pm 5^o $,
which, together with a normal mass ordering with $m_1=0$, will enable Littlest
Seesaw models to be tested in future neutrino experiments. | hep |
Stability of the holographic description of the Universe: We investigate the stability of the holographic description of the universe.
By treating the perturbation globally, we discover that this description is
stable, which is support for the holographic description of the universe. | hep |
The Casimir-Aharonov-Bohm effect?: The combined effect of the magnetic field background in the form of a
singular vortex and the Dirichlet boundary condition at the location of the
vortex on the vacuum of quantized scalar field is studied. We find the induced
vacuum energy density and current to be periodic functions of the vortex flux
and holomorphic functions of the space dimension. | hep |
Towards the matrix model of M-theory on a lattice: The Wilson discretization of the dimensionally reduced supersymmetric
Yang-Mills theory is constructed. This gives a lattice version of the matrix
model of M-theory. An SU(2) model is studied numerically in the quenched
approximation for D=4. The system shows canonical scaling in the continuum
limit. A clear signal for a prototype of the "black hole to strings" phase
transition is found. The pseudocritical temperature is determined and the
temperature dependence of the total size of the system is measured in both
phases. Further applications are outlined. | hep |
$η\to π^0 γγ$ decay within a chiral unitary approach
revisited: In view of the recent experimental developments on the experimental side in
the $\eta \to \pi^0 \gamma \gamma$ decay, and the fact that the Particle Data
Group in the on line edition of 2007 reports sizable changes of the radiative
decay widths of vector mesons used as input in the theoretical calculations of
\cite{eta}, a reevaluation of the decay width of the $\eta$ in this channel has
been done, reducing its uncertainty by almost a factor of two. The new input of
the PDG is used and invariant mass distributions and total widths are compared
with the most recent results from AGS, MAMI and preliminary ones of KLOE. The
agreement of the theory with the AGS and MAMI data is very good, both for the
total rates as well as for the invariant mass distributions of the two photons. | hep |
BMN operators with a scalar fermion pair and operator mixing in N=4
Super Yang-Mills Theory: The mixings between BMN operators with two scalar impurities and those with a
scalar fermion pair are discussed to the lowest order at planar level. For this
purpose, matrix model effective vertices are calculated to O(g^3). All the
mixing patterns are explicitly obtained. | hep |
Phenomenological aspects of nonstandard supersymmetry breaking terms: In realistic supersymmetric models, very small hard supersymmetry breaking
terms generally appear. Some of them violate baryon and/or lepton number. We
discuss their possible applications to proton decay and generation of neutrino
masses. | hep |
Parity and Front-Form Quantization of Field Theories: Recently, we proposed a new front-form quantization which treated both the
$x^{+}$ and the $x^{-}$ coordinates as front-form 'times.' This quantization
was found to preserve parity explicitly. In this paper we extend this
construction to fermion fields in the context of the Yukawa theory. We quantize
this theory using a method proposed originally by Faddeev and Jackiw . We find
that $P^-$ {\it and} $P^+$ become dynamical and that the theory is manifestly
invariant under parity. | hep |
Effects of the next-to-leading order terms in the chiral SU(3)
Lagrangian on the strangeness -1 s-wave meson-baryon interactions: The meson-baryon interactions in s-wave in the strangeness S=-1 sector are
studied using a chiral unitarity approach based on the next-to-leading order
chiral SU(3) Lagrangian. The model is fitted to the large set of experimental
data in different two-body channels. Particular attention is paid to the $\Xi$
hyperon production reaction, $\bar{K} N \rightarrow K \Xi$, where the effect of
the next-to-leading order terms in the Lagrangian play a crucial role, since
the cross section of this reaction at tree level is zero. | hep |
Quantum Braided PoincarÉ Group: A new deformation of the of the Poincar\'e group and of the Minkowski
space-time is given. From the mathematical point of view this deformation is
rather quantum-braided group. Global and local structure of this
quantum-braided Poincar\'e group is investigated. A kind of ``quantum metrics''
is introduced in the $q$-Minkowski space. | hep |
A substrate for brane shells from $T\bar{T}$: A solvable current-current deformation of the worldsheet theory of strings on
$AdS_3$ has been recently conjectured to be dual to an irrelevant deformation
of the spacetime orbifold CFT, commonly referred to as single-trace $T\bar{T}$.
These deformations give rise to a family of bulk geometries which realize a
non-trivial flow towards the UV. For a particular sign of this deformation, the
corresponding three-dimensional geometry approaches $AdS_3$ in the interior,
but has a curvature singularity at finite radius, beyond which there are closed
timelike curves. It has been suggested that this singularity is due to the
presence of "negative branes," which are exotic objects that generically change
the metric signature. We propose an alternative UV-completion for these
geometries by cutting and gluing to a regular background which approaches a
linear dilaton vacuum in the UV. In the S-dual picture, a singularity
resolution mechanism known as the enhan\c{c}on induces this transition by the
formation of a shell of $D5$-branes at a fixed radial position near the
singularity. The solutions involving negative branes gain a new interpretation
in this context. | hep |
Collider Signatures of Sneutrino Cold Dark Matter: Decays of sneutrinos are considered in the case that in the presence of
lepton-number violation in the sneutrino sector the lighter tau-sneutrino is
the Lightest Supersymmetric Particle and the Cold Dark Matter in the Universe.
In such circumstances the signals from sparticle decays differ considerably
from the ``standard'' case where the lightest neutralino is the Lightest
Supersymmetric Particle and it is found that in a wide range of parameters
compatible with the sneutrino Cold Dark Matter hypothesis signatures
characteristic for such a scenario should be easily observable at for example a
Next Linear Collider. | hep |
Probing Top Changing Neutral Higgs Couplings at Colliders: The $h(125)$ boson, discovered only in 2012, is lower than the top quark in
mass, hence $t \to ch$ search commenced immediately thereafter, with current
limits at the per mille level and improving. As the $t \to ch$ rate vanishes
with the $h$-$H$ mixing angle $\cos\gamma \to 0$, we briefly review the
collider probes of the top changing $tcH/tcA$ coupling $\rho_{tc}$ of the
exotic $CP$-even/odd Higgs bosons $H/A$. Together with an extra top conserving
$ttH/ttA$ coupling $\rho_{tt}$, one has an enhanced $cbH^+$ coupling alongside
the familiar $tbH^+$ coupling, where $H^+$ is the charged Higgs boson. The main
processes we advocate are $cg \to tH/A \to tt\bar c,\; tt\bar t$ (same-sign top
and triple-top), and $cg \to bH^+ \to bt\bar b$. We also discuss some related
processes such as $cg \to thh$, $tZH$ that depend on $\cos\gamma$ being
nonzero, comment briefly on $gg \to H/A \to t\bar t, t\bar c$ resonant
production, and touch upon the $\rho_{tu}$ coupling. | hep |
Holographic Entanglement Entropy of Mass-deformed ABJM Theory: We investigate the effect of supersymmetry preserving mass deformation near
the UV fixed point represented by the ${\cal N}=6$ ABJM theory. In the context
of the gauge/gravity duality, we analytically calculate the leading small mass
effect on the renormalized entanglement entropy (REE) for the most general
Lin-Lunin-Maldacena (LLM) geometries in the cases of the strip and disk shaped
entangling surfaces. Our result shows that the properties of the REE in
(2+1)-dimensions are consistent with those of the $c$-function in
(1+1)-dimensions. We also discuss the validity of our computations in terms of
the curvature behavior of the LLM geometry in the large $N$ limit and the
relation between the correlation length and the mass parameter for a special
LLM solution. | hep |
The lift of type IIA supergravity with D6 sources: M-theory with torsion: This paper is concerned with an extension of the well known Kaluza-Klein
mechanism. As the standard ansatz for Kaluza-Klein reduction implies the
existence of a gauge potential associated with the KK field strength, it
follows immediately that this field strength satisfies its Bianchi identity.
Hence, the standard KK formalism breaks down in the presence of a violated
Bianchi identity. This occurs for example in the context of D6 sources.
We will investigate and partially solve this problem in the context of the
type IIA/M-theory duality. Our discussion is motivated by the construction of
gauge/string duals with backreacting flavor branes using D6-branes, which
appear in M-theory as KK-monopoles. We are able to derive source-modified
equations of motion for the eleven-dimensional theory, and are subsequently
able to obtain the source-modified type IIA equations by direct dimensional
reduction. | hep |
Study of the structure of e+e- -> b bbar g events and improved limits on
the anomalous chromomagnetic coupling of the b-quark: The structure of e+e- -> bbg events was studied using Z0 decays recorded in
the SLD experiment at SLAC. Three-jet final states were selected and the
CCD-based vertex detector was used to identify two of the jets as b or bbar.
Distributions of the gluon energy and polar angle were measured over the full
kinematic range, and compared with perturbative QCD predictions. The energy
distribution is potentially sensitive to an anomalous b chromomagnetic moment
kappa. We measured kappa to be consistent with zero and set limits on its
value, -0.11 < kappa < 0.08 at 95% c.l. (preliminary). | hep |
Charged lepton Flavor Violation in Supersymmetry with Bilinear R-Parity
Violation: The simplest unified extension of the Minimal Supersymmetric Standard Model
with bi-linear R-parity violation naturally predicts a hierarchical neutrino
mass spectrum, suitable to explain atmospheric and solar neutrino fluxes. We
study whether the individual violation of the lepton numbers L_{e,mu,tau} in
the charged sector can lead to measurable rates for BR(mu->e gamma)and
$BR(tau-> mu gamma). We find that some of the R-parity violating terms that are
compatible with the observed atmospheric neutrino oscillations could lead to
rates for mu->e gamma measurable in projected experiments. However, the Delta
m^2_{12} obtained for those parameters is too high to be compatible with the
solar neutrino data, excluding therefore the possibility of having measurable
rates for mu->e gamma in the model. | hep |
Algebraic structure of gravity in Ashtekar variables: The BRST transformations for gravity in Ashtekar variables are obtained by
using the Maurer-Cartan horizontality conditions. The BRST cohomology in
Ashtekar variables is calculated with the help of an operator $\delta$
introduced by S.P. Sorella, which allows to decompose the exterior derivative
as a BRST commutator. This BRST cohomology leads to the differential invariants
for four-dimensional manifolds. | hep |
Gauge Independence of the Lagrangian Path Integral in a Higher-Order
Formalism: We propose a Lagrangian path integral based on gauge symmetries generated by
a symmetric higher-order $\Delta$-operator, and demonstrate that this path
integral is independent of the chosen gauge-fixing function. No explicit change
of variables in the functional integral is required to show this. | hep |
Higgs Production in Association with a Dark-Z at Future Electron
Positron Colliders: In recent years there have been many proposals for new electron-positron
colliders, such as the Circular Electron-Positron Collider, the International
Linear Collider, and the Future Circular Collider in electron-positron mode.
Much of the motivation for these colliders is precision measurements of the
Higgs boson and searches for new electroweak states. Hence, many of these
studies are focused on energies above the $h\,Z$ threshold. However, there are
proposals to run these colliders at the lower $WW$ threshold and $Z$-pole
energies. In this paper, we propose a new search for Higgs physics accessible
at lower energies: $e^+e^-\rightarrow h\,Z_d$, where $Z_d$ is a new light gauge
boson such as a dark photon or dark-$Z$. Such searches can be conducted at the
$WW$ threshold, i.e. energies below the $h\,Z$ threshold where exotic Higgs
decays can be searched for in earnest. Additionally, due to very good angular
and energy resolution at future electron-positron colliders, these searches
will be sensitive to $Z_d$ masses below 1 GeV, which is lower than the current
direct LHC searches. We will show that at $\sqrt{s}=160$ GeV with 10 ab$^{-1}$,
a search for $e^+e^-\rightarrow h\,Z_d$ is sensitive to $h-Z-Z_d$ couplings of
$\delta\sim 8\times 10^{-3}$ and cross sections of $\sim 1-2$ ab for $Z_d$
masses below 1 GeV. The results are similar at $\sqrt{s}=240$ GeV with 5
ab$^{-1}$. | hep |
Critical flavour number of the Thirring model in three dimensions: The Thirring model is a four fermion theory with vector interaction. We study
it in three dimensions, where it is closely related to QED and other models
used to describe properties of graphene. In addition it is a good toy model to
study chiral symmetry breaking, since a phase with broken chiral symmetry is
present for the model with one fermion flavour. On the other hand, there is no
such phase in the limit of infinitely many fermion flavours. Thus, a transition
at some critical flavour number Nfc is expected, where the broken phase
vanishes. The model was already studied with different methods, including
Schwinger-Dyson, functional renormalization group and lattice approaches. Most
studies agree that there is indeed a phase transition from a chirally symmetric
phase to a spontaneously broken phase for a small number of fermion flavours.
But there is no agreement on the critical flavour number and further details of
the critical behaviour. Values of Nfc found in the literature usually range
between 2 and 7. All earlier lattice studies were performed with staggered
fermions, where it is questionable if the continuum limit of the lattice model
has the same chiral symmetry as the continuum model. We present an approach for
simulations of the Thirring model with SLAC fermions. With this choice, we can
be sure to implement the full chiral symmetry of the continuum model. First
results from simulations are shown but do not allow a reliable estimate of Nfc
so far. | hep |
Bosonic Seesaw in the Unparticle Physics: Recently, conceptually new physics beyond the Standard Model has been
proposed by Georgi, where a new physics sector becomes conformal and provides
"unparticle" which couples to the Standard Model sector through higher
dimensional operators in low energy effective theory. Among several
possibilities, we focus on operators involving the (scalar) unparticle, Higgs
and the gauge bosons. Once the Higgs develops the vacuum expectation value
(VEV), the conformal symmetry is broken and as a result, the mixing between the
unparticle and the Higgs boson emerges. In this paper, we consider a natural
realization of bosonic seesaw in the context of unparticle physics. In this
framework, the negative mass squared or the electroweak symmetry breaking
vacuum is achieved as a result of mass matrix diagonalization. In the
diagonalization process, it is important to have zero value in the
(1,1)-element of the mass matrix. In fact, the conformal invariance in the
hidden sector can actually assure the zero of that element. So, the bosonic
seesaw mechanism for the electroweak symmetry breaking can naturally be
understood in the framework of unparticle physics. | hep |
Reactor-based Neutrino Oscillation Experiments: The status of neutrino oscillation searches employing nuclear reactors as
sources is reviewed. This technique, a direct continuation of the experiments
that proved the existence of neutrinos, is today an essential tool in
investigating the indications of oscillations found in studying neutrinos
produced in the sun and in the earth's atmosphere. The low-energy of the
reactor \nuebar makes them an ideal tool to explore oscillations with small
mass differences and relatively large mixing angles.
In the last several years the determination of the reactor anti-neutrino flux
and spectrum has reached a high degree of accuracy. Hence measurements of these
quantities at a given distance L can be readily compared with the expectation
at L = 0, thus testing \nuebar disappearance.
While two experiments, Chooz and Palo Verde, with baselines of about 1 km and
thus sensitive to the neutrino mass differences associated with the atmospheric
neutrino anomaly, have collected data and published results recently, an
ambitious project with a baseline of more than 100 km, Kamland, is preparing to
take data. This ultimate reactor experiment will have a sensitivity sufficient
to explore part of the oscillation phase space relevant to solar neutrino
scenarios. It is the only envisioned experiment with a terrestrial source of
neutrinos capable of addressing the solar neutrino puzzle. | hep |
Kinks in higher derivative scalar field theory: We study static kink configurations in a type of two-dimensional higher
derivative scalar field theory whose Lagrangian contains second-order
derivative terms of the field. The linear fluctuation around arbitrary static
kink solutions is analyzed. We find that, the linear spectrum can be described
by a supersymmetric quantum mechanics problem, and the criteria for stable
static solutions can be given analytically. We also construct a superpotential
formalism for finding analytical static kink solutions. Using this formalism we
first reproduce some existed solutions and then offer a new solution. The
properties of our solution is studied and compared without those preexisted. We
also show the possibility in constructing twinlike model in the higher
derivative theory, and give the consistency conditions for twinlike models
corresponding to the canonical scalar field theory. | hep |
Exploiting stellar explosion induced by the QCD phase transition in
large-scale neutrino detectors: The centers of the core-collapse supernovae are one of the densest
environments in the Universe. Under such conditions, it is conceivable that a
first-order phase transition from ordinary nuclear matter to the quark-gluon
plasma occurs. This transition releases a large amount of latent heat that can
drive a supernova explosion and may imprint a sharp signature in the neutrino
signal. We show how this snap feature, if observed at large-scale neutrino
detectors, can set competitive limits on the neutrino masses and assist the
localization of the supernova via triangulation. The 95\%C.L. limit on the
neutrino mass can reach 0.16~eV in Ice-Cube, 0.22~eV in Hyper-Kamiokande, and
0.58~eV in DUNE, for a supernova at a distance of 10 kpc. For the same distance
and in the most optimistic neutrino conversion case, the triangulation method
can constrain the $1\sigma$ angular uncertainty of the supernova localization
within $\sim 0.3^{\circ}-9.0^{\circ}$ in the considered pairs of the detectors,
leading to an improvement up to an order of magnitude with respect to the often
considered in the literature rise time of the neutronization burst. | hep |
The phase structure and effective action of 3D CDT at higher spatial
genus: We perform a detailed investigation of the phase structure and the
semiclassical effective action of (2+1)-dimensional Causal Dynamical
Triangulations (CDT) quantum gravity using computer simulations. On the one
hand, we study the effect of enlarging the ensemble of triangulations by
relaxing the simplicial manifold conditions in a controlled way. On the other
hand, we cast a first look at CDT geometries with spatial topology beyond that
of the sphere or torus. We measure the phase structure of the model for several
triangulation ensembles and spatial topologies, finding evidence that the phase
structure is qualitatively unaffected by these generalizations. Furthermore, we
determine the effective action for the spatial volumes of the system, again
varying the simplicial manifold conditions and the spatial topology. In all
cases where we were able to gather sufficient statistics, we found the
resulting effective action to be consistent with a minisuperspace action
derived from continuum Einstein gravity. We interpret our overall results as
evidence that 1) partially relaxing simplicial manifold conditions or changing
the spatial genus does not affect the continuum limit of 3D CDT and that 2)
increasing the spatial genus of the system likely does not influence the
leading-order terms in the emergent effective action. | hep |
Jet Function with a Jet Algorithm in SCET: The jet function for the factorized cross section $e^+e^-$ into dijets is
given as a function of the jet invariant mass s and with a generic jet
algorithm at $\mathcal{O}(\alpha_s)$. We demonstrate the results using the
Sterman-Weinberg algorithm and show that the jet function is independent of the
energy fraction $\beta$ of the soft radiation. The anomalous dimension has the
same form with and without the cone half-angle $\delta$. The dependence of the
finite part of the jet function on the cone angle is given. | hep |
Casimir effect for fermion condensate in conical rings: The fermion condensate (FC) is investigated for a (2+1)-dimensional massive
fermionic field confined on a truncated cone with an arbitrary planar angle
deficit and threaded by a magnetic flux. Different combinations of the boundary
conditions are imposed on the edges of the cone. They include the bag boundary
condition as a special case. By using the generalized Abel-Plana-type summation
formula for the series over the eigenvalues of the radial quantum number, the
edge-induced contributions in the FC are explicitly extracted. The FC is an
even periodic function of the magnetic flux with the period equal to the flux
quantum. Depending on the boundary conditions, the condensate can be either
positive or negative. For a massless field the FC in the boundary-free conical
geometry vanishes and the nonzero contributions are purely edge-induced
effects. This provides a mechanism for time-reversal symmetry breaking in the
absence of magnetic fields. Combining the results for the fields corresponding
to two inequivalent irreducible representations of the Clifford algebra, the FC
is investigated in the parity and time-reversal symmetric fermionic models and
applications are discussed for graphitic cones. | hep |
On Cosmological Perturbations on a Brane in an Anti-de Sitter Bulk: In this paper, we consider cosmological perturbations on a brane universe
embedded in an Anti-de Sitter bulk. We use a novel gauge, in which the full
five-dimensional problem is in principle solvable. In this gauge we derive the
equations for scalar, vector and tensor perturbations. These equations are
necessary in order to calculate microwave background anisotropies in this
particular scenario. Throughout the paper, we draw attention to the influence
of the bulk gravitons, which act as a source for the perturbations on the
brane. In addition, we find that isocurvature modes are generated due to the
influence of bulk gravitons. | hep |
On T-duality transformations for the three-sphere: We study collective T-duality transformations along one, two and three
directions of isometry for the three-sphere with H-flux. Our aim is to obtain
new non-geometric backgrounds along lines similar to the example of the
three-torus. However, the resulting backgrounds turn out to be geometric in
nature. To perform the duality transformations, we develop a novel procedure
for non-abelian T-duality, which follows a route different compared to the
known literature, and which highlights the underlying structure from an
alternative point of view. | hep |
S-duality wall of SQCD from Toda braiding: Exact field theory dualities can be implemented by duality domain walls such
that passing any operator through the interface maps it to the dual operator.
This paper describes the S-duality wall of four-dimensional ${\cal N}=2$ SU(N)
SQCD with 2N hypermultiplets in terms of fields on the defect, namely
three-dimensional ${\cal N}=2$ SQCD with gauge group U(N-1) and 2N flavours,
with a monopole superpotential. The theory is self-dual under a duality found
by Benini, Benvenuti and Pasquetti, in the same way that T[SU(N)] (the
S-duality wall of ${\cal N}=4$ super Yang-Mills) is self-mirror. The
domain-wall theory can also be realized as a limit of a USp(2N-2) gauge theory;
it reduces to known results for N=2. The theory is found through the AGT
correspondence by determining the braiding kernel of two semi-degenerate vertex
operators in Toda CFT. | hep |
$\bar{K}NN$ Absorption within the Framework of the Fixed Center
Approximation to Faddeev equations: We present a method to evaluate the $\bar{K}$ absorption width in the bound
$\bar{K}NN$ system. Most calculations of this system ignore this channel and
only consider the $\bar{K}N \rightarrow \pi \Sigma$ conversion. Other works
make a qualitative calculation using perturbative methods. Since the $
\Lambda(1405) $ resonance is playing a role in the process, the same resonance
is changed by the presence of the absorption channels and we find that a full
nonperturbative calculation is called for, which we present here. We employ the
Fixed Center Approximation to Faddeev equations to account for $\bar{K}$
rescattering on the $ (NN) $ cluster and we find that the width of the states
found previously for $ S=0 $ and $ S=1 $ increases by about 30 MeV due to the
$\bar{K}NN$ absorption, to a total width of about 80 MeV. | hep |
Effects of a strong magnetic field on the QCD flux tube: In this work we investigate the effect of an external magnetic field B on the
shape of flux tubes in QCD by means of lattice simulations, performed with
N_f=2+1 flavors of stout improved dynamical staggered quarks with physical
masses. After having discussed some difficulties in the practical definition of
the flux tube at B=0, we show that these ambiguities do not affect the
determination of the flux tube modifications induced by the magnetic field.
Different results are obtained depending on the relative orientations of the
flux tube and of the magnetic field: they confirm that the magnetic field acts
as transverse confinement catalyser and longitudinal confinement inhibitor;
moreover, the flux tube itself loses its axial symmetry when it is not directed
along the magnetic background. | hep |
W-Geometries: It is shown that, classically, the W-algebras are directly related to the
extrinsic geometry of the embedding of two-dimensional manifolds with chiral
parametrisation (W-surfaces) into higher dimensional K\"ahler manifolds. We
study the local and the global geometries of such embeddings, and connect them
to Toda equations. The additional variables of the related KP hierarchy are
shown to yield a specific coordinate system of the target-manifold, and this
allows us to prove that W-transformations are simply particular diffeomorphisms
of this target space. The W-surfaces are shown to be instantons of the
corresponding non-linear $\sigma$-models. | hep |
N=4, d=1 Supersymmetric Hyper-Kaehler Sigma Models and Non-Abelian
Monopole Background: We construct a Lagrangian formulation of \Nf supersymmetric mechanics with
hyper-K\"{a}hler sigma models in a bosonic sector in the non-Abelian background
gauge field. The resulting action includes a wide class of \Nf supersymmetric
mechanics describing the motion of an isospin-carrying particle over spaces
with non-trivial geometry. In two examples we discuss in details, the
background fields are identified with the field of BPST instantons in the flat
and Taub-NUT spaces. | hep |
Minicharged Particles at Accelerators: Progress and Prospects: Minicharged particles (mCPs), hypothetical free particles with tiny electric
charges below the elementary charge, $e$, offer a valuable probe of dark
sectors and fundamental physics through several clear experimental signatures.
Various models of physics beyond the Standard Model predict the existence of
such particles, which could help elucidate the ongoing mysteries regarding
electric charge quantization and the nature of dark matter. Moreover, a
hypothetical scenario involving a small minicharged subcomponent of dark matter
has recently been demonstrated as a viable explanation of the anomaly in the 21
cm hydrogen absorption signal reported by the EDGES collaboration. Although
several decades of indirect observations and direct experimental searches for
mCPs at particle accelerators have led to severe constraints, a substantial
window of the mCP mass$\unicode{x2013}$mixing parameter space remains
unexplored at the energy frontier accessible to current state-of-the-art
accelerators, such as the Large Hadron Collider (LHC). Consequently, mCPs have
remained topical over the years, and new experimental searches at accelerators
have been gaining interest. In this article, we review the theoretical
frameworks in which mCPs emerge and their phenomenological implications, the
current direct and indirect constraints on mCPs, and the present state of the
ongoing and upcoming searches for mCPs at particle accelerators. Additionally,
we present the results of an updated study of the projected sensitivity of the
recently approved (and relocated) Phase-1 detector of the MoEDAL's Apparatus
for Penetrating Particles (MAPP) experiment to Drell$\unicode{x2013}$Yan
pair-produced mCPs at the LHC's Run 3 and the future High-Luminosity LHC. | hep |
Gravitational Correction to Running of Gauge Couplings: We calculate the contribution of graviton exchange to the running of gauge
couplings at lowest non-trivial order in perturbation theory. Including this
contribution in a theory that features coupling constant unification does not
upset this unification, but rather shifts the unification scale. When
extrapolated formally, the gravitational correction renders all gauge couplings
asymptotically free. | hep |
Production of Z'-Boson Resonances with Large Width at the LHC: Di-lepton searches for Beyond the Standard Model (BSM) Z' bosons that rely on
the analysis of the Breit-Wigner (BW) line shape are appropriate in the case of
narrow resonances, but likely not sufficient in scenarios featuring Z' states
with large widths. Conversely, alternative experimental strategies applicable
to wide Z' resonances are much more dependent than the default bump search
analyses on the modelling of QCD higher-order corrections to the production
processes, for both signal and background. For heavy Z' boson searches in the
di-lepton channel at the CERN Large Hadron Collider (LHC), the transverse
momentum q_T of the di-lepton system peaks at q_T \ltap 10^{-2} M_{ll}, where
M_{ll} is the di-lepton invariant mass. We exploit this to treat the QCD
corrections by using the logarithmic resummation methods in M_{ll} / q_T to all
orders in the strong coupling constant \alpha_s. We carry out studies of Z'
states with large width at the LHC by employing the program {\tt reSolve},
which performs QCD transverse momentum resummation up to
Next-to-Next-to-Leading Logarithmic (NNLL) accuracy. We consider two benchmark
BSM scenarios, based on the Sequential Standard Model (SSM) and dubbed `SSM
wide' and `SSM enhanced'. We present results for the shape and size of Z' boson
signals at the differential level, mapped in both cross section (\sigma) and
Forward-Backward Asymmetry (A_{\rm FB}), and perform numerical investigations
of the experimental sensitivity at the LHC Run 3 and High-Luminosity LHC
(HL-LHC). | hep |
Interference Fragmentation Functions and Valence Quark Spin
Distributions in the Nucleon: We explore further applications of the twist-two quark interference
fragmentation functions introduced earlier. We show that semi-inclusive
production of two pions in the current fragmentation region in deep inelastic
scattering of a longitudinally polarized electron on a longitudinally polarized
nucleon can provide a probe of the valence quark spin (or helicity difference)
distribution in the nucleon. | hep |
A status report concerning theoretical predictions for various kaon
decays: A short overview of theoretical predictions for various kaon decays is
presented. Particular attention is devoted to pure and radiative nonleptonic
decays in the framework of Chiral Perturbation Theory. The relevance of KLOE's
future results to improve our knowledge of kaon physics and more generally of
the Standard Model at low energy is also emphasized. | hep |
TASI 2014 Lectures: The Hunt for Dark Matter: These lectures, given at the 2014 Theoretical Advanced Study Institute
(TASI), are an introduction to what we know at present about dark matter and
the major current experimental and observational efforts to identify what it
consists of. They attempt to present the complexities of the subject, making
clear common simplifying assumptions, to better understand the reach of dark
matter searches. | hep |
A trial to find an elliptic quantum algebra for $sl_2$ using the
Heisenberg and Clifford algebra: A Heisenberg-Clifford realization of a deformed $U(sl_{2})$ by two parameters
$p$ and $q$ is discussed. The commutation relations for this deformed algebra
have interesting connection with the theta functions. | hep |
Compton scattering in the Endpoint Model: We use the Endpoint model for exclusive hadronic processes to study Compton
scattering of the proton. The parameters of the Endpoint model are fixed using
the data for $F_1$ and the ratio of Pauli and Dirac form factors ($F_2/F_1$)
and then used to get numerical predictions for the differential scattering
cross section. We studied the Compton scattering at fixed $\theta_{CM}$ in the
$s \sim t \gg \Lambda_{QCD}$ limit and at fixed $s$ much larger than $t$ limit.
We observed that the calculations in the Endpoint Model give a good fit with
experimental data in both regions. | hep |
Circularly polarized gravitational waves in Chern-Simons gravity
originated from an axion domain wall: We study a scattering problem of gravitational waves (GWs) by an axion domain
wall in Chern-Simons (CS) gravity. We find that circular polarization of GWs is
produced after passing through the domain wall. It turns out that the circular
polarization is sizable if the frequency of the GW is comparable to a critical
value determined by the characteristic CS length scale and the energy scale of
the axion domain wall. Thus, observations of the circular polarization could
give a stringent constraint on the characteristic CS length scale or could be a
new avenue to search for axion. | hep |
Model analysis of thermal UV-cutoff effects on the chiral critical
surface at finite temperature and chemical potential: We study the effects of temporal UV-cutoff on the chiral critical surface in
hot and dense QCD using a chiral effective model. Recent lattice QCD
simulations indicate that the curvature of the critical surface might change
toward the direction in which the first order phase transition becomes stronger
on increasing the number of lattice sites. To investigate this effect on the
critical surface in an effective model approach, we use the Nambu-Jona-Lasinio
model with finite Matsubara frequency summation. We find that qualitative
feature of the critical surface does not alter appreciably as we decrease the
summation number, which is unlike the case what is observed in the recent
lattice QCD studies. This may either suggest the dependence of chemical
potential on the coupling strength or due to some additional interacting terms
such as vector interactions which could play an important role at finite
density. | hep |
Fermion Zero Modes and Cosmological Constant: A general condition for the existence of fermion zero modes is derived for
the M-5-brane, the M-2-brane and the D=4, N=2 Majumdar-Papapetrou 0-brane. The
fermion zero modes of these p-branes do not exist if the supersymmetry spinor
generator goes to a constant at the horizon and they exist only if it vanishes
there. In particular it is shown that the fermion zero mode of the M-2-brane in
D=11 can be forbidden from existence if Rarita-Schwinger gamma tracelessness
condition is imposed on the gravitino field. Non-existence of fermion zero mode
is interpreted, in analogy to the three dimensional example of Becker et.al.,
as a world with zero cosmological constant without supersymmetric excited
states. Also derived are the spin of the M-5-brane and its 3-form electric and
magnetic dipole moments. | hep |
Non-planar BCFW Grassmannian Geometries: In this paper, we study non-adjacent BCFW recursion relations and their
connection to positive geometry. For an adjacent BCFW shift, the $n$-point
N$^k$MHV tree-level amplitude in ${\cal N}=4$ SYM theory is expressed as a sum
over planar on-shell diagrams, corresponding to canonical dlog forms on the
cells in the positive Grassmannian $G_+(k,n)$. Non-adjacent BCFW shifts
naturally lead to an expansion of the amplitude in terms of a different set of
objects, which do not manifest the cyclic ordering and the hidden Yangian
symmetry of the amplitude. We show that these terms can be interpreted as dlog
forms on the non-planar Grassmannian geometries, generalizing the cells of the
positive Grassmannian $G_+(k,n)$ to a larger class of objects which live in
$G(k,n)$. We focus mainly on the case of NMHV amplitudes and discuss in detail
the Grassmannian geometries. We also propose an alternative way to calculate
the associated on-shell functions and dlog forms using an intriguing connection
between Grassmannian configurations and the geometry in the kinematical space. | hep |
Searching Higgs in Noncommutative Electroweak Model at Photon-Photon
Collider: We discuss the process of Higgs boson production in $\gamma\gamma$ collider
on noncommutative spacetime and compare the results with large extra dimension
in KK graviton channel. Summing all KK mode on IR brane, the affections are in
the same order by comparing noncommutatve model prediction. This process is
completely forbidden in standard model on unitarity condition and bosonic
distribution. In noncommutative theory, the effect is induced by the
coordinates noncommutable relation, $[x^{\mu}, x^{\nu}]$ = $i\theta^{\mu\nu}$.
Due to the constant background strength tensor does not contain any conserved
quantum number, hence, this effort is indicated into particle power spectrum.
Particle mass spectrum is corrected by radiational and anisotropic
surroundings. The process of $\gamma\gamma\to H^{0}H^{0}$ restricts the
unitarity condition in noncommutative field theory. Under power law
conservation condition, the neutral Higgs mass below gauge boson resonance will
produce a accelerated phenomena as the central energy is higher than $Z_{0}$
gauge boson creation scale. The effects generated from the vast light Higgs
particles descend the power rate energy distribution as far as the ambient is
under a balance. The fractional rate on polarized polars are very small
embedded into the unpolarized surroundings depend on background electric field
couplings. | hep |
Measurement of the Resonance Parameters of the $χ_{1}(1^3P_1)$ and
$χ_{2}(1^3P_2)$ States of Charmonium formed in Antiproton-Proton
Annihilations: We have studied the $^3P_J$ ($\chi_c)$ states of charmonium in formation by
antiproton-proton annihilations in experiment E835 at the Fermilab Antiproton
Source. We report new measurements of the mass, width, and $B(\chi_{cJ} \to
\bar{p} p) \times \Gamma(\chi_{cJ} \to J/\psi + anything)$ for the $\chi_{c1}$
and $\chi_{c2}$ by means of the inclusive reaction $\bar{p}p \to \chi_{cJ}
\to J/\psi + anything \to (e^{+}e^{-}) +anything $. Using the subsample of
events where $\chi_{cJ} \to \gamma + J/\psi \to \gamma + (e^{+}e^{-}) $ is
fully reconstructed, we derive $B(\chi_{cJ} \to \bar p p)\times
\Gamma(\chi_{cJ} \to J/\psi + \gamma) $. We summarize the results of the E760
(updated) and E835 measurements of mass, width and $ B(\chi_{cJ} \to \bar{p}p)
\Gamma(\chi_{cJ} \to J/\psi+\gamma)$ (J=0,1,2) and discuss the significance of
these measurements. | hep |
CP violation including universal one-loop corrections and heterotic
M-theory: CP violation by soft supersymmetry-breaking terms in orbifold
compactifications is investigated. We include the universal part of the
moduli-dependent threshold corrections in the construction of the
non-perturbative effective potential due to gaugino-condensation. This allows
interpolation of the magnitude of CP violating phases between the weakly and
strongly coupled regimes. We find that the universal threshold corrections have
a large effect on the CP violating phases in the weakly coupled regime. | hep |
DBI-Curvaton: In this paper, we study a curvaton model described by a
Dirac-Born-Infeld-like action. We calculate the spectrum of curvature
perturbation induced by DBI-curvaton and estimate its non-Gaussianity. We find
that in the limit of low sound speed the amplitude of curvature perturbation is
enhanced more than that in DBI inflation. This result also means that the
inflationary scale with DBI-curvaton may be lower than that in usual curvaton
model. In addition, we also find that the local non-Gaussianity level in
DBI-curvaton is generally about 10 times larger than that in usual curvaton
model, which is interesting for current observations. This work in some sense
explores a new application of brane-cosmology in inflation. | hep |
Coherent Showers in Decays of Colored Resonances: We present a new approach to coherent parton showers in the decays of
coloured resonances, based on the notion of "resonance-final" (RF) QCD
antennae. A full set of mass- and helicity-dependent $2\to 3$ antenna functions
are defined, with the additional requirement of positivity over the respective
branching phase spaces. Their singularity structure is identical to that of
initial-final (IF) antennae in $2\to N$ hard processes (once mass terms
associated with the incoming legs are allowed for), but the phase-space
factorisations are different. The consequent radiation patterns respect QCD
coherence (at leading colour) and reduce to
Dokshitzer-Gribov-Lipatov-Altarelli-Parisi and eikonal kernels in the
respective collinear and soft limits. The main novelty in the phase-space
factorisation is that branchings in RF antennae impart a collective recoil to
the other partons within the same decay system. An explicit implementation of
these ideas, based on the Sudakov veto algorithm, is provided in the VINCIA
antenna-shower plug-in to the PYTHIA 8 Monte Carlo event generator. We apply
our formalism, matched to next-to-leading order accuracy using POWHEG, to top
quark production at the LHC, and investigate implications for direct
measurement of the top quark mass. Finally, we make recommendations for
assessing theoretical uncertainties arising from parton showers in this
context. | hep |
Static QCD Potential at r < 1/Lambda_QCD: Perturbative expansion and
operator-product expansion: We analyze the static QCD potential V_QCD(r) in the distance region 0.1 fm <
r < 1 fm using perturbative QCD and OPE as basic theoretical tools. We assemble
theoretical developments up to date and perform a solid and accurate analysis.
The analysis consists of 3 major steps: (I) We study large-order behavior of
the perturbative series of V_QCD(r) analytically. (II) In the frame of OPE, we
define two types of renormalization schemes for the leading Wilson coefficient.
(III) We compare numerically perturbative predictions of the Wilson coefficient
and lattice computations of V_QCD(r). We perform fits to simultaneously
determine non-perturbative contribution and the relation between lattice scale
and Lambda_MSbar. (Short version) | hep |
Plasma Effects on Lasing of Uniform Ultralight Axion Condensate: Lasing of ultralight axion condensate into photons can be sensitive to the
presence of a background plasma owing to its coupling to electromagnetism. Such
a scenario is particularly relevant for superradiant axion condensate around
stellar mass black holes since the axion mass can be within a few orders of
magnitude of the plasma frequency of the surrounding medium. In this paper I
discuss the properties of the plasma around a black hole and analyze its
effects on the lasing of a uniform axion condensate of mass of the order of the
plasma frequency. | hep |
Emergent Majorana Mass and Axion Couplings in Superfluids: Axions (in the general sense) may acquire qualitatively new couplings inside
superfluids. Their conventional couplings to fermions, in empty space, involve
purely imaginary masses; the new couplings involve emergent Majorana masses.
The possibility of weak links for axions, recently put forward, is analyzed,
rejected, and replaced with a non-local analogue. | hep |
The contribution of off-shell gluons to the structure functions F_2^c
and F_L^c$ and the unintegrated gluon distributions: We calculate the perturbative parts of the structure functions $F_2^c$ and
$F_L^c$ for a gluon target having nonzero transverse momentum squared at order
$\alpha_s$. The results of the double convolution (with respect to the Bjorken
variable $x_B$ and the transverse momentum) of the perturbative part and the
unintegrated gluon densities are compared with HERA experimental data for
$F_2^c$. The contribution from $F_L^c$ structure function ranges (10-30)% of
that of $F_2^c$ at the kinematical range of HERA experiments. | hep |
One-loop quantization of rigid spinning strings in $AdS_3 \times S^3
\times T^4$ with mixed flux: We compute the one-loop correction to the classical dispersion relation of
rigid closed spinning strings with two equal angular momenta in the $AdS_3
\times S^3 \times T^4$ background supported with a mixture of R-R and NS-NS
three-form fluxes. This analysis is extended to the case of two arbitrary
angular momenta in the pure NS-NS limit. We perform this computation by means
of two different methods. The first method relies on the Euler-Lagrange
equations for the quadratic fluctuations around the classical solution, while
the second one exploits the underlying integrability of the problem through the
finite-gap equations. We find that the one-loop correction vanishes in the pure
NS-NS limit. | hep |
Lagrangian Formulations of Self-dual Gauge Theories in Diverse
Dimensions: In this work, we study Lagrangian formulations for self-dual gauge theories,
also known as chiral $n$-form gauge theories, for $n = 2p$ in $D = 4p+2$
dimensional spacetime. Motivated by a recent formulation of M5-branes derived
from the BLG model, we generalize the earlier Lagrangian formulation based on a
decomposition of spacetime into $(D-1)$ dimensions plus a special dimension, to
construct Lagrangian formulations based on a generic decomposition of spacetime
into $D'$ and $D" = D - D'$ dimensions. Although the Lorentz symmetry is not
manifest, we prove that the action is invariant under modified Lorentz
transformations. | hep |
Transverse Momentum Spectra of Pions at LHC Energies: In order to characterize the transverse momentum spectra of positive pions
measured in the ALICE experiment, two thermal approaches are utilized; one is
based on degeneracy of non-perfect Bose-Einstein gas and the other imposes an
{\it ad-hoc} finite pion-chemical potential. The inclusion of missing haron
states and the out-of-chemical equilibrium greatly contribute to the excellent
characterization of pion production. The excellent reproduction of the
experimental data can be understood as a manifestation of not-yet-regarded
anomalous pion-production, which likely contribute to the long-standing debate
on the {\it "anomalous"} proton-to-pion ratios at top RHIC and LHC energies. | hep |
Dark Freeze-out Cogenesis: We propose a new mechanism where a multi-component dark sector generates the
observed dark matter abundance and baryon asymmetry and thus addresses the
coincidence between the two. The thermal freeze-out of dark matter annihilating
into meta-stable dark partners sets the dark matter relic abundance while
providing the out-of-equilibrium condition for baryogenesis. The meta-stable
state triggers baryon asymmetry production by its decay well after the
freeze-out and potentially induces a period of early matter domination before
its decay. The dark matter and baryon abundances are related through number
conservation within the dark sector (cogenesis). The "coincidence" is a natural
outcome with GeV- to TeV-scale symmetric dark matter and the dark sector's
interactions with the Standard Model quarks. We present a UV-complete model and
explore its phenomenological predictions, including dark matter direct
detection signals, LHC signatures of new massive particles with color charges
and long-lived particles with displaced vertices, dark matter-induced nucleon
conversions, (exotic) dark matter indirect detection signals, and effects on
the cosmological matter power spectrum. As a side result, we provide a novel
analytical treatment for dark sector freeze-out, which may prove useful in the
study of related scenarios. | hep |
Finite volume effects with stationary wave solution from
Nambu--Jona-Lasinio model: In this paper, we use the two-flavor Nambu-Jona-Lasinio (NJL) model with the
proper time regularization to study the finite-volume effects of QCD chiral
phase transition.
Within a cubic volume of finite size $L$, we choose the stationary wave
condition (SWC) as the real physical spatial boundary conditions of quark
fields and compare our results with that by means of commonly used
(anti-)period boundary condition (APBC or PBC). It is found that the results by
means of SWC are obviously different to the results from the APBC or PBC.
Although the three boundary conditions give the same chiral crossover
transition curve in the infinite volume limit, the limit size $L_0$ (when
$L\geq L_{0}$, the chiral quark condensate $-\left\langle { \bar \psi \psi}
\right\rangle_L$ is indistinguishable from that at $L=\infty$) using SWC is
$L_0\approx 500$ fm which is much larger than the results obtained using APBC
or PBC. More importantly, $L_0\approx 500$ fm is also much large than the
typical size of the quark-gluon plasma produced by the relativistic heavy ion
collisions. This means that the finite volume effects play a very important
role in Relativistic Heavy Ion Collisions. In addition, we also found that when
$L\leq 2$ fm, even at zero temperature the chiral symmetry is effectively
restored. Furthermore, to quantitatively reflect the finite volume effects on
the QCD chiral phase transition, we introduce a new vacuum susceptibility,
$\chi_{1/L}(T)=-\frac{\partial \left\langle { \bar \psi \psi}
\right\rangle}{\partial (1/L)}$. With this new vacuum susceptibility, it is
very interesting to find $\chi_{1/L}(T=0)=\chi_{1/L}(T=1/L)$ for SWC. | hep |
Gravitational instanton, inflation and cosmological constant: Quantum fluctuation of unstable modes about gravitational instantons causes
the instability of flat space at finite temperature, leading to the spontaneous
process of nucleating quantum black holes. The density of vacuum energy-gain in
such process gives the cosmological term in the Einstein equation. This
naturally results in the inflationary phase of Early Universe. While the
reheating phase is attributed to the Hawking radiation of these quantum black
holes. In the Standard cosmology era, this cosmological term depends on the
reheating temperature and asymptotically approaches to the cosmological
constant in matter domination phase, consistently with current observations. | hep |
Charm and Bottom Production Measurements at the LHC: Early data of the ATLAS and CMS experiments at the LHC will allow us to
measure the cross sections for beauty and heavy quarkonia production in
proton-proton collisions at a center-of-mass energy of 14 TeV to a reasonable
precision. Different experimental approaches employing single or di-muon
triggered events and b-tagging methods are discussed. The potential for
extracting the polarization of vector states from the decays J/psi to mu+ mu-
and Y to mu+ mu- is presented. | hep |
Geometric engineering of (framed) BPS states: BPS quivers for N=2 SU(N) gauge theories are derived via geometric
engineering from derived categories of toric Calabi-Yau threefolds. While the
outcome is in agreement of previous low energy constructions, the geometric
approach leads to several new results. An absence of walls conjecture is
formulated for all values of N, relating the field theory BPS spectrum to large
radius D-brane bound states. Supporting evidence is presented as explicit
computations of BPS degeneracies in some examples. These computations also
prove the existence of BPS states of arbitrarily high spin and infinitely many
marginal stability walls at weak coupling. Moreover, framed quiver models for
framed BPS states are naturally derived from this formalism, as well as a
mathematical formulation of framed and unframed BPS degeneracies in terms of
motivic and cohomological Donaldson-Thomas invariants. We verify the
conjectured absence of BPS states with "exotic" SU(2)_R quantum numbers using
motivic DT invariants. This application is based in particular on a complete
recursive algorithm which determine the unframed BPS spectrum at any point on
the Coulomb branch in terms of noncommutative Donaldson-Thomas invariants for
framed quiver representations. | hep |
Quantum Kramers-Wannier Duality And Its Topology: We show for any oriented surface, possibly with a boundary, how to generalize
Kramers-Wannier duality to the world of quantum groups. The generalization is
motivated by quantization of Poisson-Lie T-duality from the string theory.
Cohomologies with quantum coefficients are defined for surfaces and their
meaning is revealed. They are functorial with respect to some glueing
operations and connected with q-invariants of 3-folds. | hep |
Non-standard interactions from the future neutrino solar sector: The next-generation neutrino experiment JUNO will determine the solar
oscillation parameters - $\sin^2 \theta_{12}$ and $\Delta m^2_{21}$ - with
great accuracy, in addition to measuring $\sin^2\theta_{13}$, $\Delta
m^2_{31}$, and the mass ordering. In parallel, the continued study of solar
neutrinos at Hyper-Kamiokande will provide complementary measurements in the
solar sector. In this paper, we address the expected sensitivity to
non-universal and flavour-changing non-standard interactions (NSI) with
$d$-type quarks from the combination of these two future neutrino experiments.
We also show the robustness of their measurements of the solar parameters
$\sin^2 \theta_{12}$ and $\Delta m^2_{21}$ in the presence of NSI. We study the
impact of the exact experimental configuration of the Hyper-Kamiokande
detector, and conclude it is of little relevance in this scenario. Finally, we
find that the LMA-D solution is expected to be present if no additional input
from non-oscillation experiments is considered. | hep |
Rapidity Gaps Between Jets: An excess of events with a rapidity gap between jets, over what would be
expected from non-diffractive processes, has been observed at HERA. A process
based on a perturbative QCD calculation of colour singlet exchange has been
added to HERWIG. With this addition, HERWIG is able to describe the number of
events with a gap between jets over the number without a gap. This gap fraction
is predicted to rise at large rapidity intervals between jets which would only
be visible if the detector coverage were increased. | hep |
Gauging Spacetime Symmetries on the Worldsheet and the Geometric
Langlands Program: We study the two-dimensional twisted (0,2) sigma-model on various smooth
complex flag manifolds G/B, and explore its relevance to the geometric
Langlands program. We find that an equivalence - at the level of the
holomorphic chiral algebra - between a bosonic string on G/B and a B-gauged
version of itself on G, will imply an isomorphism of classical W-algebras and a
level relation which underlie a geometric Langlands correspondence for
G=SL(N,C). This furnishes an alternative physical interpretation of the
geometric Langlands correspondence for G=SL(N,C), to that demonstrated earlier
by Kapustin and Witten via an electric-magnetic duality of four-dimensional
gauge theory. Likewise, the Hecke operators and Hecke eigensheaves will have an
alternative physical interpretation in terms of the correlation functions of
local operators in the holomorphic chiral algebra of a quasi-topological
sigma-model without boundaries. A forthcoming paper will investigate the
interpretation of a ``quantum'' geometric Langlands correspondence for
G=SL(N,C) in a similar setting, albeit with fluxes of the sigma-model moduli
which induce a ``quantum'' deformation of the relevant classical algebras
turned on. | hep |
Rare Semileptonic $B_{s}$ Decays to $η$ and $η'$ mesons in QCD: We analyze the rare semileptonic $B_s \to (\eta, \eta') l^+ l^-$, $(l=e, \mu,
\tau)$ and $B_s \to (\eta, \eta') \nu \bar{\nu}$ transitions probing the $\bar
s s$ content of the $\eta$ and $\eta'$ mesons via three--point QCD sum rules.
We calculate responsible form factors for these transitions in full theory.
Using the obtained form factors, we also estimate the related branching
fractions and longitudinal lepton polarization asymmetries. Our results are in
a good consistency with the predictions of the other existing nonperturbative
approaches. | hep |
Little String Instanton Partition Functions and Scalar Propagators: We discuss a class of Little String Theories (LSTs) whose low energy
descriptions are supersymmetric gauge theories on the $\Omega$-background with
gauge group $U(N)$ and matter in the adjoint representation. We show that the
instanton partition function of these theories can be written in terms of
Kronecker-Eisenstein series, which in a particular limit of the deformation
parameters of the $\Omega$-background organise themselves into Greens functions
of free scalar fields on a torus. We provide a concrete identification between
(differences of) such propagators and Nekrasov subfunctions. The latter are
also characterised by counting specific holomorphic curves in a Calabi-Yau
threefold $X_{N,1}$ which engineers the LST. Furthermore, using the formulation
of the partition function in terms of the Kronecker-Eisenstein series, we argue
for new recursive structures which relate higher instanton contributions to
products of lower ones. | hep |
Shockwaves in Supernovae: New Implications on the Diffuse Supernova
Neutrino Background: We investigate shock wave effects upon the diffuse supernova neutrino
background using dynamic profiles taken from hydrodynamical simulations and
calculating the neutrino evolution in three flavors with the S-matrix
formalism. We show that the shock wave impact is significant and introduces
modifications of the relic fluxes by about $20 \%$ and of the associated event
rates at the level of $10-20 \%$. Such an effect is important since it is of
the same order as the rate variation introduced when different oscillation
scenarios (i.e. hierarchy or $\theta_{13}$) are considered. In addition, due to
the shock wave, the rates become less sensitive to collective effects, in the
inverted hierarchy and when $\sin^2 2 \theta_{13}$ is between the Chooz limit
and $10^{-5}$. We propose a simplified model to account for shock wave effects
in future predictions. | hep |
Quantum Electric Field Fluctuations and Potential Scattering: Some physical effects of time averaged quantum electric field fluctuations
are discussed. The one loop radiative correction to potential scattering are
approximately derived from simple arguments which invoke vacuum electric field
fluctuations. For both above barrier scattering and quantum tunneling, this
effect increases the transmission probability. It is argued that the shape of
the potential determines a sampling function for the time averaging of the
quantum electric field operator. We also suggest that there is a
nonperturbative enhancement of the transmission probability which can be
inferred from the probability distribution for time averaged electric field
fluctuations. | hep |
Form Factors of $B_{u,d,s}$ Decays into P-Wave Axial-Vector Mesons in
the Light-Cone Sum Rule Approach: We calculate the vector and axial-vector form factors of $B_{u,d,s}$ decays
into P-wave axial-vector mesons in the light-cone sum rule approach. For the
sum rule results, we have included corrections of order $m_A/m_b$, where $m_A$
is the mass of the axial-vector meson $A$. The results are relevant to the
light-cone distribution amplitudes of the axial-vector mesons. It is important
to note that, owing to the $G$-parity, the chiral-even two-parton light-cone
distribution amplitudes of the $^3P_1$ ($^1P_1$) mesons are symmetric
(antisymmetric) under the exchange of quark and anti-quark momentum fractions
in the SU(3) limit. For chiral-odd light-cone distribution amplitudes, it is
the other way around. The predictions for decay rates of $B_{u,d,s} \to A e
\nu_e$ are also presented. | hep |
FEWZ 2.0: A code for hadronic Z production at next-to-next-to-leading
order: We introduce an improved version of the simulation code FEWZ (Fully Exclusive
W and Z Production) for hadron collider production of lepton pairs through the
Drell-Yan process at next-to-next-to-leading-order (NNLO) in the strong
coupling constant. The program is fully differential in the phase space of
leptons and additional hadronic radiation. The new version offers users
significantly more options for customization. FEWZ now bins multiple,
user-selectable histograms during a single run, and produces parton
distribution function (PDF) errors automatically. It also features a
signifcantly improved integration routine, and can take advantage of multiple
processor cores locally or on the Condor distributed computing system. We
illustrate the new features of FEWZ by presenting numerous phenomenological
results for LHC physics. We compare NNLO QCD with initial ATLAS and CMS
results, and discuss in detail the effects of detector acceptance on the
measurement of angular quantities associated with Z-boson production. We
address the issue of technical precision in the presence of severe phase-space
cuts. | hep |
Gauge conditions for an Abelian Chern-Simons system consistent with
equations of motion: Complete constraint analysis and choice of gauge conditions consistent with
equations of motion is done for Abelian Chern Simons field interacting
minimally with a complex scalar field. The Dirac-Schwinger consistency
condition is satisfied by the reduced phase space Hamiltonian density with
respect to the the Dirac bracket. It is shown that relativistic invariance
under boosts can be obtained only if gauge conditions were chosen consistent
with the equations of motion. Moreover all gauge invariant quantities are shown
to be free of transformation anomaly. | hep |
Five Jet Production with Heavy Quarks at $e^+ e^-$ Colliders: Heavy quark production in five jet events at $e^+e^-$ colliders is studied at
tree level using helicity amplitudes. Total production rates for $2b3j$ and
$4bj$ are given and compared with the corresponding results for massless
quarks. The process $e^+e^-\rightarrow q\bar q gg\gamma$ which is the dominant
contribution to $4j\gamma$ production is briefly discussed. | hep |
Indirect searches for sterile neutrinos at a high-luminosity Z-factory: A future high-luminosity $Z$-factory will offer the possibility to study rare
$Z$ decays, as those leading to lepton flavour violating final states.
Processes such as $Z \to \ell_1^\mp \ell_2^\pm$ are potentially complementary
to low-energy (high-intensity) observables of lepton flavour violation. In this
work we address the impact of new sterile fermions on lepton flavour violating
$Z$ decays, focusing on potential searches at FCC-ee (TLEP), and taking into
account experimental and observational constraints on the sterile states. We
consider a minimal extension of the Standard Model by one sterile fermion
state, and two well-motivated frameworks of neutrino mass generation, the
Inverse Seesaw embedded into the Standard Model, and the $\nu$MSM. Our study
shows that sterile neutrinos can give rise to contributions to BR($Z \to
\ell_1^\mp \ell_2^\pm$) within reach of the FCC-ee. We also discuss the
complementarity between a high-luminosity $Z$-factory and low-energy charged
lepton flavour violation facilities. | hep |
Shift of Symmetries of Naive Fermions in QCD-like Lattice Theories: We study the global symmetries of naive lattices Dirac operators in QCD-like
theories in any dimension larger than two. In particular we investigate how the
chosen number of lattice sites in each direction affects the global symmetries
of the Dirac operator. These symmetries are important since they do not only
determine the infra-red spectrum of the Dirac operator but also the symmetry
breaking pattern and, thus, the lightest pseudo-scalar mesons. We perform the
symmetry analysis and discuss the possible zero modes and the degree of
degeneracy of the lattice Dirac operators. Moreover we explicitly identify a
"reduced" lattice Dirac operator which is the naive Dirac operator apart from
the degeneracy. We verify our predictions by comparing Monte Carlo simulations
of QCD-like theories in the strong coupling limit with the corresponding random
matrix theories. | hep |
Giant Gravitons, Harish-Chandra integrals, and BPS states in symplectic
and orthogonal $\mathcal{N}$= 4 SYM: We find generating functions for half BPS correlators in $\mathcal{N}=4$ SYM
theories with gauge groups $Sp(2N)$, $SO(2N+1)$, and $SO(2N)$ by computing the
norms of a class of BPS coherent states. These coherent states are built from
operators involving Harish-Chandra integrals. Such operators have an
interpretation as localized giant gravitons in the bulk of anti-de-Sitter
space. This extends the analysis of \cite{Berenstein:2022srd} to $Sp(2N)$,
$SO(2N+1)$, and $SO(2N)$ gauge theories. We show that we may use ordinary Schur
functions as a basis for the sector of states with no cross-caps in these
theories. This is consistent with the construction of these theories as
orientifold projections of an $SU(2N)$ theory. We make note of some relations
between the symmetric functions that appear in the expansion of these coherent
states and symplectic Schur functions. We also comment on some connections to
Schubert calculus and Gromov-Witten invariants, which suggest that the
Harish-Chandra integral may be extended to such problems. | hep |
Quantum Gravity, Torsion, Parity Violation and all that: We discuss the issue of parity violation in quantum gravity. In particular,
we study the coupling of fermionic degrees of freedom in the presence of
torsion and the physical meaning of the Immirzi parameter from the viewpoint of
effective field theory. We derive the low-energy effective lagrangian which
turns out to involve two parameters, one measuring the non-minimal coupling of
fermions in the presence of torsion, the other being the Immirzi parameter. In
the case of non-minimal coupling the effective lagrangian contains an
axial-vector interaction leading to parity violation. Alternatively, in the
case of minimal coupling there is no parity violation and the effective
lagrangian contains only the usual axial-axial interaction. In this situation
the real values of the Immirzi parameter are not at all constrained. On the
other hand, purely imaginary values of the Immirzi parameter lead to violations
of unitarity for the case of non-minimal coupling. Finally, the effective
lagrangian blows up for the positive and negative unit imaginary values of the
Immirzi parameter. | hep |
Candidates for Inelastic Dark Matter: Although we have yet to determine whether the DAMA data represents a true
discovery of new physics, among such interpretations inelastic dark matter
(IDM) can match the energy spectrum of DAMA very well while not contradicting
the results of other direct detection searches. In this paper we investigate
the general properties that a viable IDM candidate must have and search for
simple models that realize these properties in natural ways. We begin by
determining the regions of IDM parameter space that are allowed by direct
detection searches including DAMA, paying special attention to larger IDM
masses. We observe that an inelastic dark matter candidate with electroweak
interactions can naturally satisfy observational constraints while
simultaneously yielding the correct thermal relic abundance. We comment on
several other proposed dark matter explanations for the DAMA signal and
demonstrate that one of the proposed alternatives -- elastic scattering of dark
matter off electrons -- is strongly disfavored when the modulated and
unmodulated DAMA spectral data are taken into account. We then outline the
general essential features of IDM models in which inelastic scattering off
nuclei is mediated by the exchange of a massive gauge boson, and construct
natural models in the context of a warped extra dimension and supersymmetry. | hep |
New brane-like solutions in modified four-dimensional
Einstein-Gauss-Bonnet gravity: We investigate solutions of a new $4D$ Einstein-Gauss-Bonnet gravity. We
first describe the bulk vacuum solution, then we add a massive probe scalar
field, and we follow considering a self-interacting scalar field which acts as
a source to support thick brane solutions in the four-dimensional
Einstein-Gauss-Bonnet scenario with a single extra dimension of infinite
extent. We illustrate our results with some distinct brane-like configurations
engendering controllable thickness. | hep |
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