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SMEFT is falsifiable through multi-Higgs measurements (even in the
absence of new light particles): From the embedding of the Standard Model Effective Field Theory (SMEFT) in
the more general Higgs Effective Field Theory (HEFT), we expose correlations
among the coefficients of the latter that, if found to be violated in future
data, would lead to the experimental falsification of the SMEFT framework.
These are derived from the necessary symmetric point of HEFT and analyticity of
the SMEFT Lagrangian that allows the construction of the SMEFT expansion, as
laid out by other groups, and properties at that point of the Higgs-flare
function $\mathcal{F}(h)$ coupling Goldstone and Higgs bosons, of the Higgs
potential $V(h)$ and of the Higgs-top quark coupling function $\mathcal{G}(h)$. | hep |
FCNC in the 3-3-1 model with right-handed neutrinos: Flavor changing neutral currents coming from a new non-universal neutral
Gauge-Boson and from the non-unitary quark mixing matrix for the
$SU(3)_c\otimes SU(3)_L\otimes U(1)_X$ model with right handed neutrinos are
studied. By imposing as experimental constraints the measured values of the 3x3
quark mixing matrix, the neutral meson mixing, and the bounds measured values
for direct flavor changing neutral current processes, the largest mixing of the
known quarks with the exotic ones can be established, with new sources of
flavor changing neutral currents being identified. Our main result is that for
a $|V_{tb}|$ value smaller than one, large rates of rare top decays such as
$t\to c\gamma$, $t\to cZ$, and $t\to cg$ (where g stands for the gluon field)
are obtained; but if $|V_{tb}|\approx 1$ the model can survive present
experimental limits only if the mass of the new neutral Gauge Boson becomes
larger that 10 TeV. | hep |
Gluon Digitization via Character Expansion for Quantum Computers: Efficient digitization is required for quantum simulations of gauge theories.
Schemes based on discrete subgroups use a smaller, fixed number of qubits at
the cost of systematic errors. We systematize this approach by deriving the
single plaquette action through matching the continuous group action to that of
a discrete one via group character expansions modulo the field fluctuation
contributions. We accompany this scheme by simulations of pure gauge over the
largest discrete crystal-like subgroup of $SU(3)$ up to the fifth-order in the
coupling constant. | hep |
Born-Infeld Gravity Revisited: In this paper we investigate the behavior of linearized gravitational
excitation in the Born-Infeld Gravity in $AdS_3$ space. We obtain the
linearized equation of motion and show that this higher order gravity propagate
two gravitons, massless and massive, on the $AdS_3$ background. In contrast to
the $R^2$ models, such as TMG or NMG, Born-Infeld Gravity does not have a
critical point for any regular choice of parameters. So the logarithmic
solution is not a solution of this model, due to this one can not find a
logarithmic conformal field theory as a dual model for Born-Infeld Gravity. | hep |
The statistical model for parton distributions: The phenomenological motivations, the expressions and the comparison with
experiment of the parton distributions inspired by the quantum statistics are
described. The Fermi-Dirac expressions for the quarks and their antiparticles
automatically account for the correlation between the shape and the first
moments of the valence partons, as well as the flavor and spin asymmetries of
the sea. One is able to describe with a small number of parameters both
unpolarized and polarized structure functions. | hep |
The Static Quark-Antiquark Potential: A ``Classical'' Experiment On The
Connection Machine CM-2: We describe the Wuppertal university pilot project in applied parallel
computing. We report on a comprehensive high statistics determination of the
static quark-antiquark potential and related quantities from quenched quantum
chromodynamics. New data for the string tension and the plaquette action for
the region 5.5 < beta < 6.8 is presented. | hep |
A power-law description of heavy ion collision centrality: The minimum-bias distribution on heavy ion collision multiplicity $n_{ch}$ is
well approximated by power-law form $n_{ch}^{-3/4}$, suggesting that a change
of variable to $n_{ch}^{1/4}$ may provide more precise access to the structure
of the distribution and to A-A collision centrality. We present a detailed
centrality study of Hijing-1.37 Monte Carlo data at 200 GeV using the power-law
format. We find that the minimum-bias distribution on $n_{participant}^{1/4}$,
determined with a Glauber Monte Carlo simulation, is uniform except for a 5%
sinusoidal variation. The power-law format reveals precise linear relations
between Glauber parameters $n_{part}$ and $n_{bin}$ and the fractional cross
section. The power-law format applied to RHIC data facilitates incorporation of
extrapolation constraints on data and Glauber distributions to obtain a
ten-fold improvement in centrality accuracy for peripheral collisions. | hep |
Four-point Functions of Lowest Weight CPOs in N=4 SYM_4 in Supergravity
Approximation: We show that the recently found quartic action for the scalars from the
massless graviton multiplet of type IIB supergravity compactified on
AdS_5\times S^5 background coincides with the relevant part of the action of
the gauged N=8 5d supergravity on AdS_5. We then use this action to compute the
4-point function of the lowest weight chiral primary operators
$\tr(\phi^{(i}\phi^{j)})$ in N=4 SYM_4 at large $N$ and at strong `t Hooft
coupling. | hep |
Charm meson resonances and D to V semileptonic form factors: Using limits of large energy effective theory and heavy quark effective
theory we propose a simple parametrization of the heavy to light H to V
semileptonic form factors. Then we reconsider D to V l nu_l decays within a
model which combines heavy meson and chiral symmetry. In our Lagrangians we
include contributions coming from excited charm meson states, some of them
recently observed. Within this framework we determine all parameters describing
the shapes of the form factors and calculate branching ratios and helicity
ratios for all D to V l nu_l decays. | hep |
Strange meson form factors in holographic QCD: We consider the electromagnetic form factors of strange vector, axial vector
and pseudoscalar mesons in a holographic QCD model. We find the charge radius
of charged kaon agrees with the experiment, while the charge radius of charged
pion is a little bit smaller than the experimental value, as obtained in other
calculations in the hard-wall holographic QCD models. The charge radii of
charged rho and $K^\ast$ quantitatively agree with a recent Dyson-Schwinger
equation calculation. We also present the electric form factors of vector,
axial vector and pseudoscalar mesons in both space-like and time-like regions.
We find the charged kaon form factor is in agreement with the experiment data. | hep |
Dark Matter spikes around Sgr A* in $γ$-rays: We use H.E.S.S. $\gamma$-ray observations of Sgr A* to derive novel limits on
the Dark Matter (DM) annihilation cross-section. We quantify their dependence
on uncertainties i) in the DM halo profile, which we vary from peaked to cored,
and ii) in the shape of the DM spike around Sgr A*, dynamically heated by the
nuclear star cluster. For peaked halo profiles and depending on the heating of
the spike, our limits are the strongest existing ones for DM masses above a few
TeV. Our study contributes to assessing the influence of the advancements in
our knowledge of the Milky Way on determining the properties of DM particles. | hep |
Dilaton Effective Action with $\mathcal{N}=1$ Supersymmetry: We clarify the structure of the four-dimensional low-energy effective action
that encodes the conformal and $U(1)$ R-symmetry anomalies in an
$\mathcal{N}=1$ supersymmetric field theory. The action depends on the dilaton,
$\tau$, associated with broken conformal symmetry, and the Goldstone mode,
$\beta$, of the broken $U(1)$ R-symmetry. We present the action for general
curved spacetime and background gauge field up to and including all possible
four-derivative terms. The result, constructed from basic principles, extends
and clarifies the structure found by Schwimmer and Theisen in arXiv:1011.0696
using superfield methods. We show that the Goldstone mode $\beta$ does not
interfere with the proof of the four-dimensional $a$-theorem based on $2 \to 2$
dilaton scattering. In fact, supersymmetry Ward identities ensure that a proof
of the $a$-theorem can also be based on $2 \to 2$ Goldstone mode scattering
when the low-energy theory preserves $\mathcal{N}=1$ supersymmetry. We find
that even without supersymmetry, a Goldstone mode for any broken global $U(1)$
symmetry cannot interfere with the proof of the four-dimensional $a$-theorem. | hep |
X-ray Lines from Dark Matter: The Good, The Bad, and The Unlikely: We consider three classes of dark matter (DM) models to account for the
recently observed 3.5 keV line: metastable excited state DM, annihilating DM,
and decaying DM. We study two examples of metastable excited state DM. The
first, millicharged composite DM, has both inelasticity and photon emission
built in, but with a very constrained parameter space. In the second example,
up-scattering and decay come from separate sectors and is thus less
constrained. The decay of the excited state can potentially be detectable at
direct detection experiments. However we find that CMB constraints are at the
border of excluding this as an interpretation of the DAMA signal. The
annihilating DM interpretation of the X-ray line is found to be in tension with
CMB constraints. Lastly, a generalized version of decaying DM can account for
the data with a lifetime exceeding the age of the Universe for masses $\lesssim
10^{6}$ GeV. | hep |
On the Geometry of Moduli Space of Vacua in N=2 Supersymmetric
Yang-Mills Theory: We consider generic properties of the moduli space of vacua in $N=2$
supersymmetric Yang--Mills theory recently studied by Seiberg and Witten. We
find, on general grounds, Picard--Fuchs type of differential equations
expressing the existence of a flat holomorphic connection, which for one
parameter (i.e. for gauge group $G=SU(2)$), are second order equations. In the
case of coupling to gravity (as in string theory), where also ``gravitational''
electric and magnetic monopoles are present, the electric--magnetic S duality,
due to quantum corrections, does not seem any longer to be related to
$Sl(2,\mathbb{Z})$ as for $N=4$ supersymmetric theory. | hep |
The Stochastic Axion Scenario: For the minimal QCD axion model it is generally believed that overproduction
of dark matter constrains the axion mass to be above a certain threshold, or at
least that the initial misalignment angle must be tuned if the mass is below
that threshold. We demonstrate that this is incorrect. During inflation, if the
Hubble scale is low, the axion tends toward an equilibrium. This means the
minimal QCD axion can naturally give the observed dark matter abundance in the
entire lower part of the mass range, down to masses $\sim 10^{-12}$ eV (or
$f_a$ up to almost the Planck scale). The axion abundance is generated by
quantum fluctuations of the field during inflation. This mechanism generates
cold dark matter with negligible isocurvature perturbations. In addition to the
QCD axion, this mechanism can also generate a cosmological abundance of
axion-like particles and other light fields. | hep |
Rigid Supersymmetric Backgrounds of 3-dimensional Newton-Cartan
Supergravity: Recently, a non-relativistic off-shell formulation of three dimensional
Newton-Cartan supergravity was proposed as the $c \rightarrow \infty$ limit of
three dimensional $\mathcal{N}=2$ supergravity in arXiv:1505.02095. In the
present paper we study supersymmetric backgrounds within this theory. Using
integrability constraints for the non-relativistic Killing spinor equations, we
explicitly construct all maximally supersymmetric solutions, which admit four
supercharges. In addition to these solutions, there are $\frac{1}{2}$-BPS
solutions with reduced supersymmetry. We give explicit examples of such
backgrounds and derive necessary conditions for backgrounds preserving two
supercharges. Finally, we address how supersymmetric backgrounds of
$\mathcal{N}=2$ supergravity are connected to the solutions found here in the
$c \rightarrow \infty$ limit. | hep |
News from polarized e- and e+ at the ILC: The proposed International Linear Collider (ILC) is well-suited for
discovering physics beyond the Standard Model and for precisely unravelling the
structure of the underlying physics. The physics return of the ILC can be
maximized by the use of polarized beams, in particular the simultaneous
polarization of the e- and the e+ beam. Ongoing physics studies are accompanied
by active R&D on the machine part for generating polarized beams and for
measuring the polarization with high precision at the ILC. Some new results on
the physics case and on the technical aspects of the polarization of both beams
are briefly summarized. | hep |
The crystallography of color superconductivity: We describe the crystalline phase of color superconducting quark matter. This
phase may occur in quark matter at densities relevant for compact star physics,
with possible implications for glitch phenomena in pulsars. We use a
Ginzburg-Landau approach to determine that the crystal has a
face-centered-cubic (FCC) structure. Moreover, our results indicate that the
phase is robust, with gaps, critical temperature, and free energy comparable to
those of the color-flavor-locked (CFL) phase. Our calculations also predict
``crystalline superfluidity'' in ultracold gases of fermionic atoms. | hep |
Lepton Masses and Mixing in a Left-Right Symmetric Model with a
TeV-scale Gravity: We construct a left-right symmetric (LRS) model in five dimensions which
accounts naturally for the lepton flavor parameters. The fifth dimension is
described by an orbifold, S_1/Z_2 times Z'_2, with a typical size of order
TeV^{-1}. The fundamental scale is of order 25 TeV which implies that the gauge
hierarchy problem is ameliorated. In addition the LRS breaking scale is of
order few TeV which implies that interactions beyond those of the standard
model are accessible to near future experiments. Leptons of different
representations are localized around different orbifold fixed points. This
explains, through the Arkani-Hamed-Schmaltz mechanism, the smallness of the tau
mass compared to the electroweak breaking scale. An additional U(1) horizontal
symmetry, broken by small parameters, yields the hierarchy in the charged
lepton masses, strong suppression of the light neutrino masses and accounts for
the mixing parameters. The model yields several unique predictions. In
particular, the branching ratio for the lepton flavor violating process mu^-
--> e^+ e^- e^- is comparable with its present experimental sensitivity. | hep |
Nonlinear SUSY General Relativity Theory and Significances: We show some consequences of the nonlinear supersymmetric general relativity
(NLSUSYGR) theory on particle physics, cosmology and their relations. They may
give new insights into the SUSY breaking mechanism, dark energy, dark matter
and the low enegy superpartner particles which are compatible with the recent
LHC data. | hep |
Quantum Anomaly in Molecular Physics: The interaction of an electron with a polar molecule is shown to be the
simplest realization of a quantum anomaly in a physical system. The existence
of a critical dipole moment for electron capture and formation of anions, which
has been confirmed experimentally and numerically, is derived. This phenomenon
is a manifestation of the anomaly associated with quantum symmetry breaking of
the classical scale invariance exhibited by the point-dipole interaction.
Finally, analysis of symmetry breaking for this system is implemented within
two different models: point dipole subject to an anomaly and finite dipole
subject to explicit symmetry breaking. | hep |
U_A(1) Anomaly in Hot and Dense QCD and the Critical Surface: We discuss the chiral phase transition in hot and dense QCD with three light
flavors. Inspired by the well known fact that the U_A(1) anomaly could induce
first order phase transitions, we study the effect of the possible restoration
of the U_A(1) symmetry at finite density. In particular, we explore the link
between the U_A(1) restoration and the recent lattice QCD results of de
Forcrand and Philipsen, in which the first order phase transition region near
zero chemical potential (mu) shrinks in the quark mass and mu space when mu is
increased. Starting from the Ginzburg-Landau theory for general discussions, we
then use the Nambu--Jona-Lasinio model for quantitative studies. With the
partial U_A(1) restoration modeled by the density dependent 't Hooft
interaction, we fit the shrinking of the critical surface found in de Forcrand
and Philipsen's lattice calculation at low mu. At higher mu, the critical
surface might shrink or expand, depending on the scenarios. This raises the
possibility that despite the shrinking of the critical surface at lower mu, the
QCD critical end point might still exist due to the expansion at higher mu. In
this case, very high precision lattice data will be needed to detect the
back-bending of the critical surface with the currently available analytic
continuation or Taylor expansion approaches. Lattice computations could,
however, test whether the U_A(1) restoration is responsible for the shrinking
of the critical surface by computing eta' mass or the topological
susceptibility at small mu. | hep |
Effective actions on squashed lens spaces: As a technical exercise with possible relevance to the holographic principle
and string theory, the effective actions (functional determinants) for scalars
and spinors on the squashed three-sphere identified under the action of a
cyclic group, Z_m, are determined. Especially in the extreme oblate squashing
limit, which has a thermodynamic interpretation, the high temperature behaviour
is found as a function of m. Although the intermediate details for odd and even
m are different, the final answers are the same. A thermodynamic interpretation
for spinors is possible only for twisted periodicity conditions and m even. | hep |
Holographic Wilson Loops, Dielectric Interfaces, and Topological
Insulators: We use holography to study (3+1)-dimensional N=4 supersymmetric SU(Nc)
Yang-Mills theory (SYM) in the large-Nc and large coupling limits, with a
(2+1)-dimensional interface where the Yang-Mills coupling or theta-angle
changes value, or "jumps." We consider interfaces that either break all
supersymmetry or that preserve half of the N=4 supersymmetry thanks to certain
operators localized to the interface. Specifically, we compute the expectation
values of a straight timelike Wilson line and of a rectangular Wilson loop in
the fundamental representation of SU(Nc). The former gives us the self-energy
of a heavy test charge while the latter gives us the potential between heavy
test charges. A jumping coupling or theta-angle acts much like a dielectric
interface in electromagnetism: a self-energy or potential includes the effects
of image charges. N=4 SYM with a jumping theta-angle may also be interpreted as
the low-energy effective description of a fractional topological insulator, as
we explain in detail. For non-supersymmetric interfaces, we find that the
self-energy and potential are qualitatively similar to those in
electromagnetism, despite the differences between N=4 SYM and electromagnetism.
For supersymmetric interfaces, we find dramatic differences from
electromagnetism which depend sensitively on the coupling of the test charge to
the adjoint scalars of N=4 SYM. In particular, we find one special case where a
test charge has vanishing image charge. | hep |
D1 and D5-brane giant gravitons on $AdS_3 \times S^3 \times S^3 \times
S^1$: We construct various examples of 1/4-BPS giant gravitons embedded into the
type IIB supergravity background $AdS_{3} \times S^{3}_{+} \times S^{3}_{-}
\times S^{1}$ with pure R-R flux: two D1-brane giants wrapping 1-cycles in
$AdS_{3}$ and $S^{3}_{+} \times S^{3}_{-}$, and one D5-brane giant wrapping a
4-cycle in $S^{3}_{+} \times S^{3}_{-}$ and the $S^{1}$. These D-branes are
supported by angular momenta $\alpha$ P on one 3-sphere and $(1-\alpha)$ P on
the other. We then construct a general class of 1/8-BPS D5-brane giant
gravitons wrapping 4-cycles $\Sigma$ in $S^{3}_{+} \times S^{3}_{-}$ and the
$S^{1}$. Here $\Sigma$ is the intersection of a holomorphic surface
$\mathcal{C}$ in $\mathbb{C}^{2}_{+} \times \mathbb{C}^{2}_{-}$ with the
$S^{3}_{+} \times S^{3}_{-}$ submanifold. The holomorphic surface $\mathcal{C}$
is defined by $f(y_{1}z_{1},y_{1}z_{2},y_{2}z_{1},y_{2}z_{2}) = 0$, with
$y_{a}$ and $z_{a}$ the $\mathbb{C}^{2}_{\pm}$ complex coordinates. There is
supersymmetry enhancement to 1/4-BPS in the special case $f(y_{1}z_{1}) = 0$ of
which our original D5-brane giant graviton is an example. | hep |
Modular invariance and entanglement entropy: We study the Renyi and entanglement entropies for free 2d CFT's at finite
temperature and finite size, with emphasis on their properties under modular
transformations of the torus. We address the issue of summing over fermion spin
structures in the replica trick, and show that the relation between
entanglement and thermal entropy determines two different ways to perform this
sum in the limits of small and large interval. Both answers are modular
covariant, rather than invariant. Our results are compared with those for a
free boson at unit radius in the two limits and complete agreement is found,
supporting the view that entanglement respects Bose-Fermi duality. We extend
our computations to multiple free Dirac fermions having correlated spin
structures, dual to free bosons on the Spin(2d) weight lattice. | hep |
Local charge conservation law as a source of gauge condition in quantum
electrodynamics: A formulation of quantum electrodynamics is proposed, in which the local law
of conservation of electric charge serves as the source of the gauge condition.
The equations of motion of the gauge variable and the density of the charge
distribution in space following from this law are introduced into the quantum
theory as additional conditions. Along with fixing the gauge, the interaction
of charges in the modified quantum theory is described by the dynamics of the
charge distribution density. The asymptotic states of free particles at spatial
infinity are replaced by the initial and final states of the electromagnetic
system in the form of charged wave packets. | hep |
Multigluon amplitudes, ${\cal N}=4$ constraints and the WZW model: Classical ${\cal N}=4$ Yang-Mills theory is defined by the superspace
constraints. We obtain a solution of a subset of these constraints and show
that it leads to the maximally helicity violating (MHV) amplitudes. The action
which leads to the solvable part of the constraints is a Wess-Zumino-Witten
(WZW) action on a suitably extended superspace. The non-MHV tree amplitudes can
also be expressed in terms of this action. | hep |
Radiative Decays of Charged Leptons in the Seesaw Effective Field Theory
with One-loop Matching: The canonical type-I seesaw model with three heavy Majorana neutrinos is one
of the most natural extensions of the standard model (SM) to accommodate tiny
Majorana masses of three ordinary neutrinos. At low-energy scales, Majorana
neutrino masses and unitarity violation of lepton flavor mixing have been
extensively discussed in the literature, which are respectively generated by
the unique dimension-five Weinberg operator and one dimension-six operator in
the seesaw effective field theory (SEFT) with the tree-level matching. In this
work, we clarify that a self-consistent calculation of radiative decays of
charged leptons $\beta^- \to \alpha^- + \gamma$ requires the SEFT with one-loop
matching, where new six-dimensional operators emerge and make important
contributions. For the first time, the Wilson coefficients of all the relevant
six-dimensional operators are computed by carrying out the one-loop matching
between the effective theory and full seesaw model, and applied to calculate
the total rates of radiative decays of charged leptons. | hep |
Is the up-quark massless?: We report on determinations of the low-energy constants alpha5 and alpha8 in
the effective chiral Lagrangian at O(p^4), using lattice simulations with N_f=2
flavours of dynamical quarks. Precise knowledge of these constants is required
to test the hypothesis whether or not the up-quark is massless. Our results are
obtained by studying the quark mass dependence of suitably defined ratios of
pseudoscalar meson masses and matrix elements. Although comparisons with an
earlier study in the quenched approximation reveal small qualitative
differences in the quark mass behaviour, numerical estimates for alpha5 and
alpha8 show only a weak dependence on the number of dynamical quark flavours.
Our results disfavour the possibility of a massless up-quark, provided that the
quark mass dependence in the physical three-flavour case is not fundamentally
different from the two-flavour case studied here. | hep |
Stable Sexaquark: It is proposed that the neutral, B=2, flavor singlet sexaquark (S) composed
of uuddss quarks, has mass m_S <~ 2 GeV. If m_S < 2 (m_p + m_e), it is
absolutely stable, while for m_S < m_p+m_e + m_Lambda, its lifetime can be
greater than the age of the Universe. Lattice gauge theory cannot yet predict
m_S, but indirect evidence supports the hypothesis of stability. A stable S is
consistent with QCD theory and would have eluded detection in accelerator and
non-accelerator experiments. If it exists, the S is a good Dark Matter
candidate. Analyses of existing Upsilon decay and LHC data can be used to
discover it and measure its mass. | hep |
Brane-Worlds and the Calabi-Yau Complex Structure Moduli: In this paper we extend previous work on the relation between the complex
structure moduli of the underlying Calabi-Yau manifold in five dimensional
supergravity with the time evolution of an embedded 3-brane. We numerically
solve the fields' equations for such a construction and focus on dust and
radiation filled branes; with the possible application of modeling the universe
as a brane-world. It is shown that in both cases the time evolution of the
moduli causally connects to the expansion of the brane-world. We also find that
in most cases considered there is an early short period of rapid accelerative
expansion, indicating an inflationary epoch. We report on these results;
leaving analysis of the underlying causes for future work. | hep |
Spinless Salpeter Equation: Laguerre Bounds on Energy Levels: The spinless Salpeter equation may be considered either as a standard
approximation to the Bethe--Salpeter formalism, designed for the description of
bound states within a relativistic quantum field theory, or as the most simple,
to a certain extent relativistic generalization of the costumary
nonrelativistic Schr\"odinger formalism. Because of the presence of the rather
difficult-to-handle square-root operator of the relativistic kinetic energy in
the corresponding Hamiltonian, very frequently the corresponding (discrete)
spectrum of energy eigenvalues cannot be determined analytically. Therefore, we
show how to calculate, by some clever choice of basis vectors in the Hilbert
space of solutions, for the rather large class of power-law potentials, at
least (sometimes excellent!) upper bounds on these energy eigenvalues, for the
lowest-lying levels this even analytically. | hep |
Pion production in neutrino-nucleus collisions: We compare our pion production results with recent MiniBooNE data measured in
mineral oil. Our total cross sections lie below experimental data for neutrino
energies above 1 GeV. Differential cross sections show our model produces too
few high energy pions in the forward direction as compared to data. The
agreement with experiment improves by artificially removing pion final state
interaction. | hep |
Neutrino mass with large $SU(2)_L$ multiplet fields: We propose an extension of the standard model introducing large $SU(2)_L$
multiplet fields which are quartet and septet scalars and quintet Majorana
fermions. These multiplets can induce the neutrino masses via interactions with
the $SU(2)$ doublet leptons. We then find the neutrino masses are suppressed by
small vacuum expectation value of the quartet/septet and an inverse of quintet
fermion mass relaxing the Yukawa hierarchies among the standard model fermions.
We also discuss collider physics at the Large Hadron Collider considering
production of charged particles in these multiplets, and due to effects of
violating custodial symmetry, some specific signatures can be found. Then we
discuss the detectability of these signals. | hep |
First observation of the decay $B_s^0 \rightarrow φ\bar{K}^{*0}$: The first observation of the decay $B_s^0 \rightarrow \phi \bar{K}^{*0}$ is
reported. The analysis is based on a data sample corresponding to an integrated
luminosity of 1.0 fb$^{-1}$ of $pp$ collisions at $\sqrt{s} = 7 TeV$, collected
with the LHCb detector. A yield of $30 \pm 6$ $B_s^0 \rightarrow
(K^+K^-)(K^-\pi^+)$ decays is found in the mass windows $1012.5 < M(K^+K^-) <
1026.5 MeV/c^2$ and $746 < M(K^-\pi^+)< 1046 MeV/c^2$. The signal yield is
found to be dominated by $B_s^0 \rightarrow \phi \bar{K}^{*0}$ decays, and the
corresponding branching fraction is measured to be ${\cal B}(B_s^0 \rightarrow
\phi \bar{K}^{*0}) = (1.10 \pm 0.24 (stat) \pm 0.14 (syst) \pm 0.08 (f_d/f_s))
\times 10^{-6}$, where the uncertainties are statistical, systematic and from
the ratio of fragmentation fractions $f_d/f_s$ which accounts for the different
production rate of $B^0$ and $B_s^0$ mesons. The significance of $B_s^0
\rightarrow \phi \bar{K}^{*0}$ signal is 6.1 standard deviations. The fraction
of longitudinal polarization in $B_s^0 \rightarrow \phi \bar{K}^{*0}$ decays is
found to be $f_0 = 0.51 \pm 0.15 (stat) \pm 0.07 (syst)$. | hep |
Superconformal Calogero models as a gauged matrix mechanics: We present basics of the gauged superfield approach to constructing
N-superconformal multi-particle Calogero-type systems developed in
arXiv:0812.4276, arXiv:0905.4951 and arXiv:0912.3508. This approach is
illustrated by the multi-particle systems possessing SU(1,1|1) and
D(2,1;\alpha) supersymmetries, as well as by the model of new N=4
superconformal quantum mechanics. | hep |
$R$-Parity Breaking Phenomenology: We review various features of the $R$-parity breaking phenomenology, with
particular attention to the low energy observables, and to the patterns of the
$R$-parity breaking interactions that arise in Grand Unified models. | hep |
Small Flux Superpotentials for Type IIB Flux Vacua Close to a Conifold: We generalize the recently proposed mechanism by Demirtas, Kim, McAllister
and Moritz arXiv:1912.10047 for the explicit construction of type IIB flux
vacua with $|W_0|\ll 1$ to the region close to the conifold locus in the
complex structure moduli space. For that purpose tools are developed to
determine the periods and the resulting prepotential close to such a
codimension one locus with all the remaining moduli still in the large complex
structure regime. As a proof of principle we present a working example for the
Calabi-Yau manifold $\mathbb{P}_{1,1,2,8,12}[24]$. | hep |
The quenched generating functional for hadronic weak interactions: The ultraviolet behaviour of the generating functional for hadronic weak
interactions with $|\Delta S| =1, 2$ is investigated to one loop for a generic
number of flavours and in the quenched approximation. New quenched chiral
logarithms generated by the weak interactions can be accounted for via a
redefinition of the weak mass term in the $\Delta S=\pm 1$ weak effective
Lagrangian at leading order. Finally, we illustrate how chiral logarithms are
modified by the quenched approximation in $K\to\pi\pi$ matrix elements with
$\Delta I=1/2$ and 3/2. | hep |
$J/ψ$ -nucleon scattering in $P_{c}^{+}$ pentaquarks channel: Two pentaquarks $P_{c}^{+}$ were discovered by LHCb collaboration as peaks in
the proton-$J/\psi$ invariant mass. We perform the lattice QCD study of the
scattering between $J/\psi$ meson and nucleon in the channels with
$J^{P}=\frac{3}{2}^{+},\frac{3}{2}^{-}, \frac{5}{2}^{+}, \frac{5}{2}^{-}$,
where $P_{c}^{+}$ was discovered. This is the first lattice simulation that
reaches the energies $4.3-4.5~$GeV where pentaquarks reside. The higher partial
waves $L>0$ are also explored for the first time. In this study we consider the
single-channel approximation for scattering of $NJ/\psi$. Energies and
eigenstates are extracted for the $NJ/\psi$ system at the zero total momentum
for all six irreducible representations of the lattice irreducible
representation. No significant energy shifts are observed. The number of
eigenstates agrees with the number expected from non-interacting limit for
scattering. This could possibly indicate that the $P_{c}$ resonances seen in
experiment are a consequence of a coupling of the $NJ/\psi$ channel with other
two-hadron channels. | hep |
Determination of $c_\mathrm A$ in three-flavour lattice QCD with Wilson
fermions and tree-level improved gauge action: We report on an ongoing non-perturbative determination of the improvement
coefficient of the axial current, $c_\mathrm A$, with three flavours of
dynamical $\mathrm O(a)$ improved Wilson quarks and tree-level Symanzik
improved gauge action. Our computations are based on simulations with the
openQCD code. The improvement condition for a range of couplings is formulated
with Schr\"odinger functional boundary conditions and imposed along a line of
constant physics in parameter space. Our analysis involves correlation
functions with boundary wave functions such that a large sensitivity to
$c_\mathrm A$ can be reached by exploiting the PCAC relation with two different
pseudoscalar states. | hep |
Fresh look on triality: Investigating the $Z_3$ symmetry in Quantum Chromodynamics (QCD) we show that
full QCD with a vacuum of vanishing baryonic number does not lead to metastable
phases. Rather in QCD with dynamical fermions, the degeneracy of $Z_3$ phases
manifests itself in observables without open triality. | hep |
Quarkonium from the Fifth Dimension: Adding fundamental matter of mass m_Q to N=4 Yang Mills theory, we study
quarkonium, and "generalized quarkonium" containing light adjoint particles. At
large 't Hooft coupling the states of spin<=1 are anomalously light (Kruczenski
et al., hep-th/0304032). We examine their form factors, and show these hadrons
are unlike any known in QCD. By a traditional yardstick they appear infinite in
size (as with strings in flat space) but we show that this is a failure of the
yardstick. All of the hadrons are actually of finite size ~ \sqrt{g^2N}/m_Q,
regardless of their radial excitation level and of how many valence adjoint
particles they contain. Certain form factors for spin-1 quarkonia vanish in the
large-g^2N limit; thus these hadrons resemble neither the observed J/Psi
quarkonium states nor rho mesons. | hep |
Improving the Top Quark Forward-Backward Asymmetry Measurement at the
LHC: At the LHC, top quark pairs are dominantly produced from gluons, making it
difficult to measure the top quark forward-backward asymmetry. To improve the
asymmetry measurement, we study variables that can distinguish between top
quarks produced from quarks and those from gluons: the invariant mass of the
top pair, the rapidity of the top-antitop system in the lab frame, the rapidity
of the top quark in the top-antitop rest frame, the top quark polarization and
the top-antitop spin correlation. We combine all the variables in a likelihood
discriminant method to separate quark-initiated events from gluon-initiated
events. We apply our method on models including G-prime's and W-prime's
motivated by the recent observation of a large top quark forward-backward
asymmetry at the Tevatron. We have found that the significance of the asymmetry
measurement can be improved by 10% to 30%. At the same time, the central values
of the asymmetry increase by 40% to 100%. We have also analytically derived the
best spin quantization axes for studying top quark polarization as well as
spin-correlation for the new physics models. | hep |
Exploring Ultralight Scalar Assistance in Sterile Neutrino Dark Matter:
Cold Spectrum and Unusual X/Gamma-ray Signatures: We present a scalar-driven sterile neutrino production model where the
interaction with the ultralight scalar field modifies the oscillation
production of sterile neutrinos in the early universe. The model effectively
suppresses the production of sterile neutrinos at low temperatures due to the
heavy scalar mass, resulting in a colder matter power spectrum that avoids
constraints from small-scale structure observations. In this model, the
dominant dark matter relic is from sterile neutrinos, with only a small
fraction originating from the ultralight scalar. Furthermore, the model
predicts a detectable X/gamma-ray flux proportional to the cubic density of
local sterile neutrinos for a light scalar mass due to the light scalar
coupling to sterile neutrinos. This distinguishes our model from normal
decaying dark matter, which has a linear dependence on the density. In
addition, the model predicts a potential low-energy monochromatic neutrino
signal that can be detectable by future neutrino telescopes. | hep |
Flipped versions of the universal 3-3-1 and the left-right symmetric
models in $[SU(3)]^3$: a comprehensive approach: By considering the 3-3-1 and the left-right symmetric models as low energy
effective theories of the $SU(3)_C\otimes SU(3)_L\otimes SU(3)_R$~(for short
$[SU(3)]^3$) gauge group, alternative versions of these models are found. The
new neutral gauge bosons of the universal 3-3-1 model and its flipped versions
are presented; also, the left-right symmetric model and its flipped variants
are studied. Our analysis shows that there are two flipped versions of the
universal 3-3-1 model, with the particularity that both of them have the same
weak charges. For the left-right symmetric model we also found two flipped
versions; one of them new in the literature which, unlike those of the 3-3-1,
requires a dedicated study of its electroweak properties. For all the models
analyzed, the couplings of the $Z'$ bosons to the standard model fermions are
reported. The explicit form of the null space of the vector boson mass matrix
for an arbitrary Higgs tensor and gauge group is also presented. In the general
framework of the $[SU(3)]^3$ gauge group, and by using the LHC experimental
results and EW precision data, limits on the $Z'$ mass and the mixing angle
between $Z$ and the new gauge bosons $Z'$ are obtained. The general results
call for very small mixing angles in the range $10^{-3}$ radians and $M_{Z'}>$
2.5 TeV. | hep |
Lorentz Violation and Radiative Corrections in Gauge Theories: Various studies have already considered radiative corrections in
Lorentz-violating models unveiling many instances where a minimal or nonminimal
operator generates, via loop corrections, a contribution to the photon sector
of the Standard-Model Extension. However, an important fraction of this
literature does not follow the widely accepted conventions and notations of the
Standard-Model Extension, and this obscures the comparison between different
calculations as well as possible phenomenological consequences. After reviewing
some of these works, we uncover one example where a well defined loop
correction to the $k_{F}$ coefficient, already presented in the literature,
allows us to improve the bounds on one specific coefficient of the fermion
sector of the Lorentz-violating QED extension. | hep |
Non-perturbative rheological behavior of a far-from-equilibrium
expanding plasma: For the Bjorken flow we investigate the hydrodynamization of different modes
of the one-particle distribution function by analyzing its relativistic kinetic
equations. We calculate the constitutive relations of each mode written as a
multi-parameter trans-series encoding the non-perturbative dissipative
contributions quantified by the Knudsen $Kn$ and inverse Reynolds $Re^{-1}$
numbers. At any given order in the asymptotic expansion of each mode, the
transport coefficients get effectively renormalized by summing over all
non-perturbative sectors appearing in the trans-series. This gives an effective
description of the transport coefficients that provides a new renormalization
scheme with an associated renormalization group equation, going beyond the
realms of linear response theory. As a result, the renormalized transport
coefficients feature a transition to their equilibrium fixed point, which is a
neat diagnostics of transient non-Newtonian behavior. As a proof of principle,
we verify the predictions of the effective theory with the numerical solutions
of their corresponding evolution equations. Our studies strongly suggest that
the phenomenological success of fluid dynamics far from local thermal
equilibrium is due to the transient rheological behavior of the fluid. | hep |
The spectrum of massive excitations of 3d 3-state Potts model and
universality: We consider the mass spectrum of the 3$d$ 3-state Potts model in the broken
phase (a) near the second order Ising critical point in the temperature -
magnetic field plane and (b) near the weakly first order transition point at
zero magnetic field. In the case (a), we compare the mass spectrum with the
prediction from universality of mass ratios in the 3$d$ Ising class; in the
case (b), we determine a mass ratio to be compared with the corresponding one
in the spectrum of screening masses of the (3+1)$d$ SU(3) pure gauge theory at
finite temperature in the deconfined phase near the transition. The agreement
in the comparison in the case (a) would represent a non-trivial test of
validity of the conjecture of spectrum universality. A positive answer to the
comparison in the case (b) would suggest the possibility to extend this
conjecture to weakly first order phase transitions. | hep |
Progress in calculation of the fourth Mellin moment of the pion
light-cone distribution amplitude using the HOPE method: The pion light-cone distribution amplitude (LCDA) is a central
non-perturbative object of interest for the calculation of high-energy
exclusive processes in quantum chromodynamics. This article describes the
progress in the lattice QCD calculation of the fourth Mellin moment of the pion
LCDA using a heavy-quark operator product expansion (HOPE). | hep |
On the instantons and the hypermultiplet mass of N=2* super Yang-Mills
on S^4: We show that the physical N=4 super Yang-Mills theory on a four-sphere with
an arbitrary gauge group receives no instanton contributions, by clarifying the
relation between the hypermultiplet mass and the equivariant parameters of the
mass-deformed theory preserving N=2 supersymmetry. The correct relation also
implies that N=4 superconformal Yang-Mills theory with gauge group SU(2)
corresponds to Liouville theory on a torus with the insertion of a non-trivial
operator, rather than the identity as have been claimed in the literature. | hep |
Gluino production in some supersymmetric models at the LHC: In this article we review the mechanisms in several supersymmetric models for
producing gluinos at the LHC and its potential for discovering them. We focus
on the MSSM and its left-right extensions. We study in detail the strong sector
of both models. Moreover, we obtain the total cross section and differential
distributions. We also make an analysis of their uncertainties, such as the
gluino and squark masses, which are related to the soft SUSY breaking
parameters. | hep |
Diquark correlations in baryons: the Interacting Quark Diquark Model: A review of the underlying ideas of the Interacting Quark Diquark Model
(IQDM) that asses the baryon spectroscopy in terms of quark diquark degrees of
freedom is given, together with a discussion of the missing resonances problem.
Some ideas about its generalization the heavy baryon spectroscopy is given.s of
freedom is given, together with a discussion of the missing resonances problem.
Some ideas about its generalization the heavy baryon spectroscopy is given.The
results are compared to the existing experimental data. | hep |
Black Hole Condensation and Duality in String Theory: This is a non-technical version of a talk presented at the conference,
"S-Duality and Mirror Symmetry in String Theory" Trieste, June, 1996 which will
appear in the proceedings. | hep |
Gravitational Violation of R Parity and its Cosmological Signatures: The discrete R-parity ($R_P$) usually imposed on the Supersymmetric (SUSY)
models is expected to be broken at least gravitationally. If the neutralino is
a dark matter particle its decay channels into positrons, antiprotons and
neutrinos are severely constrained from astrophysical observations. These
constraints are shown to be violated even for Planck-mass-suppressed
dimension-five interactions arising from gravitational effects. We perform a
general analysis of gravitationally induced $R_P$ violation and identify two
plausible and astrophysically consistent scenarios for achieving the required
suppression. | hep |
Unitarity Analyses of $πN$ Elastic Scattering Amplitudes: The pion - nucleon scattering phase shifts in $s$ and $p$ waves are analyzed
using PKU unitarization approach that can separate the phase shifts into
different contributions from poles and branch cuts. It is found that in
$S_{11}$ and $P_{11}$ channels, there exist large and positive missing
contributions when one compares the phase shift from known resonances plus
branch cuts with the experimental data, which indicates that those two channels
may contain sizable effects from $N^*(1535)$ and $N^*(1440)$ shadow poles.
Those results are obtained using tree level results of the $\pi N$ amplitude. | hep |
A noncommutative-geometric interpretation of the resolution of
equivariant instanton moduli spaces: We generalize the recently proposed noncommutative ADHM construction to the
case of $\Gamma$-equivariant instantons over $\R^4$, with $\Gamma$ a Kleinian
group. We show that a certain form of the inhomogeneous ADHM equations
describes instantons over a noncommutative deformation of the Kleinian orbifold
$\C^2/\Gamma$ and we discuss the relation of this with Nakajima's description
of instantons over ALE spaces. In particular, we obtain a noncommutative
interpretation of the minimal resolution of Kleinian singularities. | hep |
Accumulation-Point Amplitudes in String Theory: We point out some common qualitative features of the Coon
amplitude$\unicode{x2014}$a family of deformations of the Veneziano amplitude
with logarithmic Regge trajectories$\unicode{x2014}$and the open string
scattering amplitude for strings ending on a D-brane in AdS. Both reduce to the
Veneziano amplitude at relatively low energies. Both systems have an
accumulation point in their spectrum, with an infinite number of states below a
certain energy. The approach to this point is very similar. Both have the same
high-energy fixed-angle behavior. Nevertheless, we find some differences in the
spectrum of states with highest angular momentum. These similarities suggest
that there may exist a string background that realizes the Coon amplitude. | hep |
Unruh detectors and quantum chaos in JT gravity: We identify the spectral properties of Hawking-Unruh radiation in the eternal
black hole at ultra low energies as a probe for the chaotic level statistics of
quantum black holes. Level repulsion implies that there are barely Hawking
particles with an energy smaller than the level separation. This effect is
experimentally accessible by probing the Unruh heat bath with a linear
detector. We provide evidence for this effect via explicit and exact
calculations in JT gravity building on a radar definition of bulk observables
in the model. Similar results are observed for the bath energy density. This
universal feature of eternal Hawking radiation should resonate into the
evaporating setup. | hep |
Chiral Aspects of Improved Staggered Fermions with 2+1-Flavors from the
HotQCD Collaboration: We present recent results from lattice simulations of 2+1 flavors of improved
staggered fermions at zero baryon number density near the high temperature
crossover. Included are new results from simulations of asqtad fermions at Nt =
12 and a nearly physical Goldstone pion mass and from simulations of HISQ
fermions at Nt = 6 and 8. We focus on observables sensitive to chiral symmetry
and confinement. A companion HotQCD talk discusses the effects of
staggered-fermion taste-symmetry breaking on thermodynamic quantities. | hep |
Bootstrapping Coulomb and Higgs branch operators: We apply the numerical conformal bootstrap to correlators of Coulomb and
Higgs branch operators in $4d$ $\mathcal{N}=2$ superconformal theories. We
start by revisiting previous results on single correlators of Coulomb branch
operators. In particular, we present improved bounds on OPE coefficients for
some selected Argyres-Douglas models, and compare them to recent work where the
same cofficients were obtained in the limit of large $r$ charge. There is solid
agreement between all the approaches. The improved bounds can be used to
extract an approximate spectrum of the Argyres-Douglas models, which can then
be used as a guide in order to corner these theories to numerical islands in
the space of conformal dimensions. When there is a flavor symmetry present, we
complement the analysis by including mixed correlators of Coulomb branch
operators and the moment map, a Higgs branch operator which sits in the same
multiplet as the flavor current. After calculating the relevant superconformal
blocks we apply the numerical machinery to the mixed system. We put general
constraints on CFT data appearing in the new channels, with particular emphasis
on the simplest Argyres-Douglas model with non-trivial flavor symmetry. | hep |
The Fundamental Constants in Physics and their Time Dependence: We discuss the fundamemtal constants in the Standard Model of particle
physics, in particular possible changes of these constants on the cosmological
time scale. The Grand Unification of the observed strong, electromagnetic and
weak interactions implies relations between time variation of the finestructure
constant alpha and the QCD scale $\Lambda_c$. The astrophysical observation of
a variation implies a time variation of $10^{-15} / year$. Several experiments
in Quantum Optics, which were designed to look for a time variation of
$\Lambda_c$, are discussed. | hep |
Carving Out the Space of 4D CFTs: We introduce a new numerical algorithm based on semidefinite programming to
efficiently compute bounds on operator dimensions, central charges, and OPE
coefficients in 4D conformal and N=1 superconformal field theories. Using our
algorithm, we dramatically improve previous bounds on a number of CFT
quantities, particularly for theories with global symmetries. In the case of
SO(4) or SU(2) symmetry, our bounds severely constrain models of conformal
technicolor. In N=1 superconformal theories, we place strong bounds on
dim(Phi*Phi), where Phi is a chiral operator. These bounds asymptote to the
line dim(Phi*Phi) <= 2 dim(Phi) near dim(Phi) ~ 1, forbidding positive
anomalous dimensions in this region. We also place novel upper and lower bounds
on OPE coefficients of protected operators in the Phi x Phi OPE. Finally, we
find examples of lower bounds on central charges and flavor current two-point
functions that scale with the size of global symmetry representations. In the
case of N=1 theories with an SU(N) flavor symmetry, our bounds on current
two-point functions lie within an O(1) factor of the values realized in
supersymmetric QCD in the conformal window. | hep |
The BRST treatment of stretched membranes: The BRST-invariant formulation of the bosonic stretched membrane is
considered. In this formulation the stretched membrane is given as a
perturbation around zero-tension membranes, where the BRST-charge decomposes as
a sum of a string-like BRST-charge and a perturbation. It is proven, by means
of cohomology techniques, that there exists to any order in perturbation theory
a canonical transformation that reduces the full BRST-charge to the string-like
one. It is also shown that one may extend the results to the quantum level
yielding a nilpotent charge in 27 dimensions. | hep |
New CP observables in B0(t) -> hyperon + antihyperon from parity
violation in the sequential decay: We consider the decay B0(t) -> hyperon + antihyperon, followed by hyperon
weak decay. We show that parity violation in the latter allows to reach new CP
observables: not only Im(lambda_f) but also Re(lambda_f) can be measured. In
the decay B0_d(t) -> Lambda LambdaBar (BR ~ 10-6), Lambda -> p pi- these
observables reduce to sin(2alpha) and cos(2alpha) in the small Penguin limit,
the latter solving the discrete ambiguity alpha -> pi/2 -alpha. For beta one
could consider the Cabibbo suppressed mode B0_d(t) -> Lambda_c Lambda_cBar (BR
\~ 10-4), Lambda_c -> Lambda pi+, p K0bar, ... (with BR ~ 10-2). The pure
Penguin modes B0_s(t)->Sigma-Sigma-Bar, Xi-Xi-Bar, Omega-Omega-Bar (BR ~ 10-7)
can be useful in the search of CP violation beyond the Standard Model. Because
of the small total rates, the study of these modes could only be done in future
high statistics experiments. Also, in the most interesting case Lambda
LambdaBar the time dependence of the asymmetry can be difficult to reconstruct.
On the other hand, we show that B_d mesons, being a coherent source of Lambda
LambdaBar, is useful to look for CP violation in Lambda decay. We also discuss
B0_d(t) -> J/Psi K*0 -> l+ l- K_S pi0 where the secondary decays conserve
parity, and angular correlations allow to determine terms of the form
cos(delta)cos(2beta), delta being a strong phase. This phase has been measured
by CLEO, but we point out that a discrete ambiguity prevents to determine
sign(cos(2beta)). However, if one assumes small strong phases, like in
factorization and as supported by CLEO data, one could have information on
sign(cos(2beta)). Similar remarks can be done for cos(2alpha) in the decay
B_d0(t) -> rho rho -> 4pi. | hep |
Product Groups, Discrete Symmetries, and Grand Unification: We present GUT models based on an $SU(5)\times SU(5)$ GUT group. These models
maintain the main successes of simple-group GUTs but permit simple solutions to
the doublet-triplet splitting problem. Moreover, GUT breaking is triggered by
supersymmetry breaking so that the GUT scale is naturally generated as a
combination of the Planck scale and the supersymmetry breaking scale. | hep |
Conformal Quivers and Melting Molecules: Quiver quantum mechanics describes the low energy dynamics of a system of
wrapped D-branes. It captures several aspects of single and multicentered BPS
black hole geometries in four-dimensional $\mathcal{N} = 2$ supergravity such
as the presence of bound states and an exponential growth of microstates. The
Coulomb branch of an Abelian three node quiver is obtained by integrating out
the massive strings connecting the D-particles. It allows for a scaling regime
corresponding to a deep AdS$_2$ throat on the gravity side. In this scaling
regime, the Coulomb branch is shown to be an $SL(2,\mathbb{R})$ invariant
multi-particle superconformal quantum mechanics. Finally, we integrate out the
strings at finite temperature---rather than in their ground state---and show
how the Coulomb branch `melts' into the Higgs branch at high enough
temperatures. For scaling solutions the melting occurs for arbitrarily small
temperatures, whereas bound states can be metastable and thus long lived.
Throughout the paper, we discuss how far the analogy between the quiver model
and the gravity picture, particularly within the AdS$_2$ throat, can be taken. | hep |
Conformally Invariant Sigma Models on Anti de Sitter Spaces,
Chern-Simons p-branes and W Geometry: Conformally invariant sigma models in $D=2n$ dimensions with target
non-compact O(2n,1) groups are studied. It is shown that despite the
non-compact nature of the O(2n,1) groups, the classical action and Hamiltonian
are positive definite. Instanton field configurations are found to correspond
geometrically to conformal ``stereographic'' mappings of $R^{2n}$ into the
Euclidean signature $AdS_{2n}$ spaces. Zaikov's relationship between Self Dual
$p$-branes and Chern-Simons $p'$-branes, provided $p=p'+1$ and the embedding
$D=p+1$-dimensional manifold is Euclidean, is elaborated further. Branes
actions can be obtained also from a Moyal deformation quantization of
Generalized Yang Mills Theories. Using this procedure, we show how four
dimensional SU(N) YM theories contain Chern-Simons membranes and hadronic bags
in the large $N$ limit. Since Chern-Simons $p'$-branes have an underlying
infinite dimensional algebra containing $W_{1+\infty}$, as shown by Zaikov, we
discuss the importance that $W$ geometry should have in the final formulation
of $M$ theory. | hep |
QCD axion bubbles from the hidden SU(N) gauge symmetry breaking: The QCD axion bubbles can be formed due to an extra Peccei-Quinn (PQ)
symmetry breaking in the early Universe. In this paper, we investigate the QCD
axion bubbles formation from the PQ symmetry broken by hidden $SU(N)_H$ gauge
interactions after inflation, which leads to the multiple vacua. The axion
acquires a light mass and then settles down into different vacua. The QCD axion
bubbles are formed when the conventional QCD axion arises during the QCD phase
transition. In our scenario, the QCD axions that start to oscillate at the
large values $\sim2\pi/3$ can lead to the high density axion bubbles with
$N=2$. The cosmological implications of the QCD axion bubbles are also
discussed, such as the primordial black holes (PBHs) and the axion
miniclusters. We find that the PBH mass is lager than
$\sim\mathcal{O}(5\times10^5)M_\odot$ for the axion scale
$f_a\sim\mathcal{O}(10^{16})\, \rm GeV$. | hep |
Leptogenesis at the TeV scale: We present a general description of the problems encountered when attempting
to build a simple model of leptogenesis and hence of baryogenesis at an energy
scale as low as 1-10 TeV. We consider three possible lepton asymmetry
enhancement mechanisms in the out-of-equilibrium decay scenario, emphasizing
the three body decay mechanism as most natural. A new model based on the three
body decays of right-handed neutrinos is proposed. It naturally allows both
leptogenesis and neutrino mass generation at low scale. Also discussed is the
possibility of inducing leptogenesis at low scale in existing neutrino mass
models: Fukugita-Yanagida model, Higgs triplet model, Zee model and models with
R-parity violation. | hep |
The top squark-mediated annihilation scenario and direct detection of
dark matter in compressed supersymmetry: Top squark-mediated annihilation of bino-like neutralinos to top-antitop
pairs can play the dominant role in obtaining a thermal relic dark matter
abundance in agreement with observations. In a previous paper, it was argued
that this can occur naturally in models of compressed supersymmetry, which
feature a running gluino mass parameter that is substantially smaller than the
wino mass parameter at the scale of apparent gauge coupling unification. Here I
study in some more detail the parameter space in which this is viable, and
compare to other scenarios for obtaining the observed dark matter density. I
then study the possibility of detecting the dark matter directly in future
experiments. The prospects are consistently very promising for a wide variety
of model parameters within this scenario. | hep |
Four-point renormalized coupling constant in O(N) models: The renormalized zero-momentum four-point coupling $g_r$ of O(N)-invariant
scalar field theories in $d$ dimensions is studied by applying the 1/N
expansion and strong coupling analysis. The O(1/N) correction to the
$\beta$-function and to the fixed point value $g_r^*$ are explictly computed.
Strong coupling series for lattice non-linear sigma models are analyzed near
criticality in d=2 and d=3 for several values of $N$ and the corresponding
values of $g_r^*$ are extracted. Large-N and strong coupling results are
compared with each other, finding a good general agreement. For small N the
strong coupling analysis in 2-d gives the best determination of $g^*_r$ to date
(or comparable for N=2,3 with the available Monte Carlo estimates), and in 3-d
it is consistent with available $\phi^4$ field theory results. | hep |
Escher in the Sky: The cosmological models called $\alpha$-attractors provide an excellent fit
to the latest observational data. Their predictions $n_{s} = 1-2/N$ and $r =
12\alpha/N^{2}$ are very robust with respect to the modifications of the
inflaton potential. An intriguing interpretation of $\alpha$-attractors is
based on a geometric moduli space with a boundary: a Poincare disk model of a
hyperbolic geometry with the radius $\sqrt{3\alpha}$, beautifully represented
by the Escher's picture Circle Limit IV. In such models, the amplitude of the
gravitational waves is proportional to the square of the radius of the Poincare
disk. | hep |
Strongly Interacting Matter at Finite Chemical Potential : Hybrid Model
Approach: Search for a proper and realistic equation of state (EOS) for strongly
interacting matter used in the study of the QCD phase diagram still appears as
a challenging problem. Recently, we constructed a hybrid model description for
the quark gluon plasma (QGP) as well as hadron gas (HG) phases where we used an
excluded volume model for HG and a thermodynamically consistent quasiparticle
model for the QGP phase. The hybrid model suitably describes the recent lattice
results of various thermodynamical as well as transport properties of the QCD
matter at zero baryon chemical potential ($\mu_{B}$). In this paper, we extend
our investigations further in obtaining the properties of QCD matter at finite
value of $\mu_{B}$ and compare our results with the most recent results of
lattice QCD calculation. | hep |
Differential equations and dispersion relations for Feynman amplitudes.
The two-loop massive sunrise and the kite integral: It is shown that the study of the imaginary part and of the corresponding
dispersion relations of Feynman graph amplitudes within the differential
equations method can provide a powerful tool for the solution of the equations,
especially in the massive case. The main features of the approach are
illustrated by discussing the simple cases of the 1-loop self-mass and of a
particular vertex amplitude, and then used for the evaluation of the two-loop
massive sunrise and the QED kite graph (the problem studied by Sabry in 1962),
up to first order in the (d-4) expansion. | hep |
Higgs boson couplings as a probe of new physics: Precise measurements of various coupling constants of the 125 GeV Higgs boson
$h$ are one of the most important and solid methods to determine the structure
of the Higgs sector. If we find deviations in the $h$ coupling constants from
the standard model predictions, it can be an indirect evidence of the existence
of additional Higgs bosons in non-minimal Higgs sectors. Furthermore, we can
distinguish non-minimal Higgs sectors by measuring a pattern of deviations in
various $h$ couplings. In this talk, we show patterns of the deviations in
several simple non-minimal Higgs sectors, especially for the gauge $hVV$ and
Yukawa $hf\bar{f}$ couplings. This talk is based on the paper [1]. | hep |
Direct Detection of Light Dark Matter from Evaporating Primordial Black
Holes: The direct detection of sub-GeV dark matter interacting with nucleons is
hampered by the low recoil energies induced by scatterings in the detectors.
This experimental difficulty is avoided in the scenario of boosted dark matter
where a component of dark matter particles is endowed with large kinetic
energies. In this Letter, we point out that the current evaporation of
primordial black holes with masses from $10^{14}$ to $10^{16}$ g is a source of
boosted light dark matter with energies of tens to hundreds of MeV. Focusing on
the XENON1T experiment, we show that these relativistic dark matter particles
could give rise to a signal orders of magnitude larger than the present upper
bounds. Therefore, we are able to significantly constrain the combined
parameter space of primordial black holes and sub-GeV dark matter. In the
presence of primordial black holes with a mass of $10^{15}~\mathrm{g}$ and an
abundance compatible with present bounds, the limits on DM-nucleon
cross-section are improved by four orders of magnitude. | hep |
Lattice QCD calculations of nucleon transverse momentum-dependent parton
distributions using clover and domain wall fermions: We present a lattice QCD calculation of transverse momentum dependent parton
distribution functions (TMDs) of protons using staple-shaped Wilson lines. For
time-reversal odd observables, we calculate the generalized Sivers and
Boer-Mulders transverse momentum shifts in SIDIS and DY cases, and for T-even
observables we calculate the transversity related to the tensor charge and the
generalized worm-gear shift. The calculation is done on two different n_f=2+1
ensembles: domain-wall fermion (DWF) with lattice spacing 0.084 fm and pion
mass of 297 MeV, and clover fermion with lattice spacing 0.114 fm and pion mass
of 317 MeV. The results from those two different discretizations are consistent
with each other. | hep |
Search for Z$γ$ resonances using leptonic and hadronic final states
in proton-proton collisions at $\sqrt{s}=$ 13 TeV: A search is presented for resonances decaying to a Z boson and a photon. The
analysis is based on data from proton-proton collisions at a center-of-mass
energy of 13 TeV, corresponding to an integrated luminosity of 35.9 fb$^{-1}$,
and collected with the CMS detector at the LHC in 2016. Two decay modes of the
Z boson are investigated. In the leptonic channels, the Z boson candidates are
reconstructed using electron or muon pairs. In the hadronic channels, they are
identified using a large-radius jet, containing either light-quark or b quark
decay products of the Z boson, via jet substructure and advanced b quark
tagging techniques. The results from these channels are combined and
interpreted in terms of upper limits on the product of the production cross
section and the branching fraction to Z$\gamma$ for narrow and broad spin-0
resonances with masses between 0.35 and 4.0 TeV, providing thereby the most
stringent limits on such resonances. | hep |
B physics at the DO Experiment at Fermilab: We discuss recent $B$ physics results from the D{\O}experiment at Fermilab.
The results presented here use data sets with integrated luminosities ranging
from $\sim 200-440 $ pb$^{-1}$, collected at the Tevatron, between April 2002
and August 2004, at a center of mass energy of $p {\bar p}$ collisions of 1.96
TeV | hep |
Impacts of the Higgs mass on vacuum stability, running fermion masses
and two-body Higgs decays: The latest results of the ATLAS and CMS experiments indicate 116 GeV \lesssim
M_H \lesssim 131 GeV and 115 GeV \lesssim M_H \lesssim 127 GeV, respectively,
for the mass of the Higgs boson in the standard model (SM) at the 95%
confidence level. In particular, both experiments point to a preferred narrow
mass range M_H \simeq (124 ... 126) GeV. We examine the impact of this
preliminary result of M_H on the SM vacuum stability by using the two-loop
renormalization-group equations (RGEs), and arrive at the cutoff scale
\Lambda_VS \sim 4 \times 10^{12} GeV (for M_H = 125 GeV, M_t = 172.9 GeV and
\alpha_s(M_Z) = 0.1184) where the absolute stability of the SM vacuum is lost
and some kind of new physics might take effect. We update the values of running
lepton and quark masses at some typical energy scales, including the ones
characterized by M_H, 1 TeV and \Lambda_VS, with the help of the two-loop RGEs.
The branching ratios of some important two-body Higgs decay modes, such as H
\to b\bar{b}, H \to \tau^+ \tau^-, H\to \gamma\gamma, H\to W^+ W^- and H \to Z
Z, are also recalculated by inputting the values of relevant particle masses at
M_H. | hep |
Planck-Scale Physics and the Peccei-Quinn Mechanism: Global-symmetry violating higher-dimension operators, expected to be induced
by Planck-scale physics, in general drastically alter the properties of the
axion field associated with the Peccei-Quinn solution to the strong-CP problem,
and render this solution unnatural. The particle physics and cosmology
associated with other global symmetries can also be significantly changed. | hep |
Investigation of Dark Matter in Minimal 3-3-1 Models: It is shown that the 3-3-1 model with the minimal lepton content can work as
two-Higgs-triplet 3-3-1 model while leaving the other scalars as inert
particles responsible for dark matter. We study two cases of dark matter
corresponding to the doublet and singlet scalar candidates. We figure out the
parameter spaces in the WMAP allowed region of the relic density. The indirect
and direct searches for dark matter in both cases are investigated by using
micrOMEGAs. | hep |
Quantum Informational Dark Energy: Dark energy from forgetting: We suggest that dark energy has a quantum informational origin. Landauer's
principle associated with the erasure of quantum information at a cosmic
horizon implies the non-zero vacuum energy having effective negative pressure.
Assuming the holographic principle, the minimum free energy condition, and the
Gibbons-Hawking temperature for the cosmic event horizon we obtain the
holographic dark energy with the parameter $d\simeq 1$, which is consistent
with the current observational data. It is also shown that both the
entanglement energy and the horizon energy can be related to Landauer's
principle. | hep |
The soft mode in the Sachdev-Ye-Kitaev model and its gravity dual: We give an exposition of the SYK model with several new results. A non-local
correction to the Schwarzian effective action is found. The same action is
obtained by integrating out the bulk degrees of freedom in a certain variant of
dilaton gravity. We also discuss general properties of out-of-time-order
correlators. | hep |
A new method for suppressing excited-state contaminations on the nucleon
form factors: One of the most challenging tasks in lattice calculations of baryon form
factors is the analysis and control of excited-state contaminations. Taking the
isovector axial form factors of the nucleon as an example, both a dispersive
representation and a calculation in chiral effective field theory show that the
excited-state contributions become dominant at fixed source-sink separation
when the axial current is spatially distant from the nucleon source location.
We address this effect with a new method in which the axial current is
localized by a Gaussian wave-packet and apply it on a CLS ensemble with
$N_f=2+1$ flavors of O($a$) improved Wilson fermions with a pion mass of
$m_\pi=200\,$MeV. | hep |
Low-Energy Parity-Violation and New Physics: The new physics sensitivity of a variety of low-energy parity-violating (PV)
observables is analyzed. A comparison is made between atomic PV for a single
isotope, atomic PV using isotope ratios, and PV electron-hadron and
electron-electron scattering. The complementarity among these observables, as
well as with high-energy processes, is emphasized. Theoretical uncertainties
entering the interpretation of low-energy measurements are discussed. | hep |
Holographic applications of logarithmic conformal field theories: We review the relations between Jordan cells in various branches of physics,
ranging from quantum mechanics to massive gravity theories. Our main focus is
on holographic correspondences between critically tuned gravity theories in
Anti-de Sitter space and logarithmic conformal field theories in various
dimensions. We summarize the developments in the past five years, include some
novel generalizations and provide an outlook on possible future developments. | hep |
Indirect dark matter searches at ultrahigh energy neutrino detectors: High to ultrahigh energy neutrino detectors can uniquely probe the properties
of dark matter $\chi$ by searching for the secondary products produced through
annihilation and/or decay processes. We evaluate the sensitivities to dark
matter thermally averaged annihilation cross section $\langle\sigma v\rangle$
and partial decay width into neutrinos $\Gamma_{\chi\rightarrow\nu\bar{\nu}}$
(in the mass scale $10^7 \leq m_\chi/{\rm GeV} \leq 10^{15}$) for next
generation observatories like POEMMA and GRAND. We show that in the range $
10^7 \leq m_\chi/{\rm GeV} \leq 10^{11}$, space-based Cherenkov detectors like
POEMMA have the advantage of full-sky coverage and rapid slewing, enabling an
optimized dark matter observation strategy focusing on the Galactic center. We
also show that ground-based radio detectors such as GRAND can achieve high
sensitivities and high duty cycles in radio quiet areas. We compare the
sensitivities of next generation neutrino experiments with existing constraints
from IceCube and updated 90\% C.L. upper limits on $\langle\sigma v\rangle$ and
$\Gamma_{\chi\rightarrow\nu\bar{\nu}}$ using results from the Pierre Auger
Collaboration and ANITA. We show that in the range $ 10^7 \leq m_\chi/{\rm GeV}
\leq 10^{11}$ POEMMA and GRAND10k will improve the neutrino sensitivity to
particle dark matter by factors of 2 to 10 over existing limits, whereas
GRAND200k will improve this sensitivity by two orders of magnitude. In the
range $10^{11} \leq m_\chi/{\rm GeV} \leq 10^{15}$, POEMMA's fluorescence
observation mode will achieve an unprecedented sensitivity to dark matter
properties. Finally, we highlight the importance of the uncertainties related
to the dark matter distribution in the Galactic halo, using the latest fit and
estimates of the Galactic parameters. | hep |
Local Gauss law and local gauge symmetries in QFT: Local gauge symmetries reduce to the identity on the observables, as well as
on the physical states (apart from reflexes of the local gauge group topology)
and therefore their use in Quantum Field Theory (QFT) asks for a justification
of their strategic role. They play an intermediate role in deriving the
validity of Local Gauss Laws on the physical states (for the currents which
generate the related global gauge group); conversely, we show that local gauge
symmetries arise whenever a vacuum representation of a local field algebra
${\cal{F}}$ is used for the description/construction of physical states
satisfying Local Gauss Laws, just as global compact gauge groups arise for the
description of localizable states labeled by superselected quantum numbers. The
above relation suggests that the Gauss operator, which by locality cannot
vanish in ${\cal{F}}$, provides an intrinsic characterization of the
realizations of a gauge QFT in terms of a local field algebra and of the
related local gauge symmetries. | hep |
Model-Independent Bottom Baryon Mass Predictions in the 1/N Expansion: Recent discoveries of the Xi_b, Sigma_b and Sigma_b^* baryons at the Tevatron
are in good agreement with model-independent mass predictions made a decade ago
based on a combined expansion in 1/N_c, 1/m_Q and SU(3) flavor symmetry
breaking. Using the new experimental data as input, mass predictions for the
undiscovered bottom baryons Xi_b^\prime, Xi_b^*, Omega_b and Omega_b^* and for
many unmeasured bottom baryon mass splittings are updated. The observed ground
state charm baryons exhibit the mass hierarchy previously predicted by the
1/N_c, 1/m_Q and SU(3) flavor breaking expansion. | hep |
Coherent Pion Production in Neutrino Nucleus Scattering: In this article, we study the coherent pion production in neutrino-nucleus
interaction in the resonance region using the formalism based on partially
conserved axial current (PCAC) theorem which relates the neutrino-nucleus cross
section to the pion-nucleus elastic cross section. The pion nucleus elastic
cross section is calculated using the Glauber model in terms of pion-nucleon
cross sections obtained by parameterizing the experimental data. We calculate
the differential and integrated cross sections for charged current coherent
pion production in neutrino carbon scattering. The results of integrated cross
section calculations are compared with the measured data. Predictions for the
differential and integrated cross sections for coherent pion productions in
neutrino iron scattering using above formalism are also made. | hep |
Physics Beyond SM at RHIC with Polarized Protons: The capabilities of RHIC with polarized protons to test the Lorentz structure
of electroweak interactions and also the properties of MSSM Higgs, should it be
discovered, are discussed. | hep |
Theory determination of $\bar{B}\to D^{(*)}\ell^-\barν$ form factors
at $\mathcal{O}(1/m_c^2)$: We carry out an analysis of the full set of ten $\bar{B}\to D^{(*)}$ form
factors within the framework of the Heavy-Quark Expansion (HQE) to order
$\mathcal{O}(\alpha_s,\,1/m_b,\,1/m_c^2)$, both with and without the use of
experimental data. This becomes possible due to a recent calculation of these
form factors at and beyond the maximal physical recoil using QCD light-cone sum
rules, in combination with constraints from lattice QCD, QCD three-point sum
rules and unitarity. We find good agreement amongst the various theoretical
results, as well as between the theoretical results and the kinematical
distributions in $\bar{B}\to D^{(*)}\lbrace e^-,\mu^-\rbrace\bar\nu$
measurements. The coefficients entering at the $1/m_c^2$ level are found to be
of $\mathcal{O}(1)$, indicating convergence of the HQE. The phenomenological
implications of our study include an updated exclusive determination of
$|V_{cb}|$ in the HQE, which is compatible with both the exclusive
determination using the BGL parametrization and with the inclusive
determination. We also revisit predictions for the lepton-flavour universality
ratios $R_{D^{(*)}}$, the $\tau$ polarization observables $P_\tau^{D^{(*)}}$,
and the longitudinal polarization fraction $F_L$. Posterior samples for the HQE
parameters are provided as ancillary files, allowing for their use in
subsequent studies. | hep |
Differential Expansion for antiparallel triple pretzels: the way the
factorization is deformed: For a peculiar family of double braid knots there is a remarkable
factorization formula for the coefficients of the differential (cyclotomic)
expansion (DE), which nowadays is widely used to construct the exclusive Racah
matrices $S$ and $\bar S$ in arbitrary representations. The origins of the
factorization remain obscure and the special role of double braids remains a
mystery. In an attempt to broaden the perspective, we extend the family of
double braids to antiparallel triple pretzels, which are obtained by the
defect-preserving deformation from the trefoil and all have defect zero. It
turns out that factorization of DE coefficients is violated quite strongly,
still remains described by an elegant formula, at least for all symmetric
representations. | hep |
Quantum Dynamics of Low-Energy Theory on Semilocal Non-Abelian Strings: Recently a low-energy effective theory on non-Abelian semilocal vortices in
SQCD with the U(N) gauge group and N + \tilde{N} quark flavors was obtained in
field theory arXiv:1104.2077. The result is exact in a certain limit of large
infrared cut-off. The resulting model was called the zn model. We study quantum
dynamics of the zn model in some detail. First we solve it at large N in the
leading order. Then we compare our results with those of Hanany and Tong
hep-th/0403158 (the HT model) who based their derivation on a certain type-IIA
formalism, rather than on a field-theory construction. In the 't Hooft limit of
infinite N both model's predictions are identical. At finite N our calculations
agree with the Hanany-Tong results only in the BPS sector. Beyond the BPS
sector there is no agreement between the zn and HT models. Finally, we study
perturbation theory of the zn model from various standpoints. | hep |
The strangest lifetime: A bizarre story of $τ(Ω_c^0)$: For a long time it has been established both experimentally and theoretically
that $\Omega_c^0$ is shortest-lived among the four singly charmed baryons which
decay weakly. The situation was dramatically changed in 2018 when LHCb reported
a new measurement of the $\Omega_c^0$ lifetime using semileptonic $b$-hadron
decays. The value is nearly four times larger than the previous world average
of $\tau(\Omega_c^0)$ and it is confirmed by the most recent LHCb measurement
with the prompt production. In this viewpoint article, we review the status and
point out that heavy quark expansion (HQE) fails to apply to $\Omega_c^0$ to
the order of $1/m_c^4$. By demanding a sensible HQE for $\Omega_c^0$ will lead
to a lifetime of $\Omega_c^0$ longer than $\Lambda_c^+$. | hep |
Autocorrelation in Updating Pure SU(3) Lattice Gauge Theory by the use
of Overrelaxed Algorithms: We measure the sweep-to-sweep autocorrelations of blocked loops below and
above the deconfinement transition for SU(3) on a $16^4$ lattice using
20000-140000 Monte-Carlo updating sweeps. A divergence of the autocorrelation
time toward the critical $\beta$ is seen at high blocking levels. The peak is
near $\beta$ = 6.33 where we observe 440 $\pm$ 210 for the autocorrelation time
of $1\times 1$ Wilson loop on $2^4$ blocked lattice. The mixing of 7 Brown-Woch
overrelaxation steps followed by one pseudo-heat-bath step appears optimal to
reduce the autocorrelation time below the critical $\beta$. Above the critical
$\beta$, however, no clear difference between these two algorithms can be seen
and the system decorrelates rather fast. | hep |
The tetrahexahedric Calogero model: We consider the spherical reduction of the rational Calogero model (of type
$A_{n-1}$, without the center of mass) as a maximally superintegrable quantum
system. It describes a particle on the $(n{-}2)$-sphere in a very special
potential. A detailed analysis is provided of the simplest non-separable case,
$n{=}4$, whose potential blows up at the edges of a spherical tetrahexahedron,
tesselating the two-sphere into 24 identical right isosceles spherical
triangles in which the particle is trapped. We construct a complete set of
independent conserved charges and of Hamiltonian intertwiners and elucidate
their algebra. The key structure is the ring of polynomials in Dunkl-deformed
angular momenta, in particular the subspaces invariant and antiinvariant under
all Weyl reflections, respectively. | hep |
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