pinecone/core-2020-05-10-deduplication huggingface dataset:
TeV Scale Universal Seesaw, Vacuum Stability and Heavy Higgs

We discuss the issue of vacuum stability of standard model by embedding it
within the TeV scale left-right universal seesaw model (called SLRM in the
text). This model has only two coupling parameters $(\lambda_1, \lambda_2)$ in
the Higgs potential and only two physical neutral Higgs bosons $(h, H)$. We
explore the range of values for $(\lambda_1, \lambda_2)$ for which the light
Higgs boson mass $M_h=126$ GeV and the vacuum is stable for all values of the
Higgs fields. Combining with the further requirement that the scalar self
couplings remain perturbative till typical GUT scales of order $10^{16}$ GeV,
we find (i) an upper and lower limit on the second Higgs $(H)$ mass to be
within the range: $0.4 \leq \frac{M_H}{v_R}\leq 0.7$, where the $v_R$ is the
parity breaking scale and (ii) that the heavy vector-like top, bottom and
$\tau$ partner fermions ($P_3, N_3, E_3$) mass have an upper bound $M_{P_3,
N_3, E_3} \leq v_R$. We discuss some phenomenological aspects of the model
pertaining to LHC.Comment: 21 pages, 7 figures, some typos corrected and references updated,
  accepted for publication in JHE
Implications of the Little Higgs Dark Matter and T-odd Fermions

We study the phenomenology of dark matter in the Littlest Higgs model with
T-parity after the discovery of Higgs boson. We analyze the relic abundance of
dark matter, focusing on the effects of coannihilaitons with T-odd fermions.
After determining the parameter space that predicts the correct relic abundance
measured by WMAP and Planck collaborations, we evaluate the elastic scattering
cross section between dark matter and nucleon. In comparison with experimental
results, we find that the lower mass of dark matter is constrained mildly by
LUX 2013 while the future XENON experiment has potential to explore most of the
parameter space for both T-odd lepton and T-odd quark coannihilation scenarios.
We also study the collider signatures of T-odd fermion pair production at the
LHC. Even though the production cross sections are large, it turns out very
challenging to search for these T-odd fermions directly at the collider because
the visible charged leptons or jets are very soft. Furthermore, we show that,
with an extra hard jet radiated out from the initial state, the T-odd quark
pair production can contribute significantly to mono-jet plus missing energy
search at the LHC
On the gauge dependence of the Standard Model vacuum instability scale

After reviewing the calculation of the Standard Model one-loop effective
potential in a class of linear gauges, we discuss the physical observables
entering the vacuum stability analysis. While the electroweak-vacuum-stability
bound on the Higgs boson mass can be formally proven to be gauge independent,
the field value at which the effective potential turns negative (the so-called
instability scale) is a gauge dependent quantity. By varying the gauge-fixing
scheme and the gauge-fixing parameters in their perturbative domain, we find an
irreducible theoretical uncertainty of at least two orders of magnitude on the
scale at which the Standard Model vacuum becomes unstable.Comment: 24 pages, 4 figures. One reference added. To appear in JHE
New Limits on Light Hidden Sectors from Fixed-Target Experiments

New physics can be light if it is hidden, coupling very weakly to the
Standard Model. In this work we investigate the discovery prospects of Abelian
hidden sectors in lower-energy fixed-target and high-precision experiments. We
focus on a minimal supersymmetric realization consisting of an Abelian vector
multiplet, coupled to hypercharge by kinetic mixing, and a pair of chiral Higgs
multiplets. This simple theory can give rise to a broad range of experimental
signals, including both commonly-studied patterns of hidden vector decay as
well as new and distinctive hidden sector cascades. We find limits from the
production of hidden states other than the vector itself. In particular, we
show that if the hidden Abelian symmetry is higgsed, and the corresponding
hidden Higgs boson has visible decays, it severely restricts the ability of the
hidden sector to explain the anomalous muon magnetic moment.Comment: 44 pages + appendices/references, 28 figures. Figures in secs 5 and 7
  updated to correct error in hadronic exclusions; limits slightly weaker, but
  qualitative conclusions unchange
Magnetic instability in AdS/CFT : Schwinger effect and Euler-Heisenberg
  Lagrangian of Supersymmetric QCD

To reveal the Schwinger effect for quarks, i.e., pair creation process of
quarks and antiquarks, we derive the vacuum decay rate at strong coupling using
AdS/CFT correspondence. Magnetic fields, in addition to the electric field
responsible for the pair creation, causes prominent effects on the rate, and is
important also in experiments such as RHIC/LHC heavy ion collisions. In this
paper, through the gravity dual we obtain the full Euler-Heisenberg Lagrangian
of N=2 supersymmetric QCD and study the Schwinger mechanism with not only a
constant electric field but also a constant magnetic field as external fields.
We determine the quark mass and temperature dependence of the Lagrangian. In
sharp contrast with the zero magnetic field case, we find that the imaginary
part, and thus the vacuum decay rate, diverges in the massless zero-temperature
limit. This may be related to a strong instability of the QCD vacuum in strong
magnetic fields. The real part of the Lagrangian serves as a generating
function for non-linear electro-magnetic responses, and is found such that the
Cotton-Mouton effect vanishes. Interestingly, our results of the Schwinger /
Cotton-Mouton effects coincide precisely with those of N=2 supersymmetric QED.Comment: 21 pages. v2:references added, footnotes adde
Scattering theory without large-distance asymptotics

In conventional scattering theory, to obtain an explicit result, one imposes
a precondition that the distance between target and observer is infinite. With
the help of this precondition, one can asymptotically replace the Hankel
function and the Bessel function with the sine functions so that one can
achieve an explicit result. Nevertheless, after such a treatment, the
information of the distance between target and observer is inevitably lost. In
this paper, we show that such a precondition is not necessary: without losing
any information of distance, one can still obtain an explicit result of a
scattering rigorously. In other words, we give an rigorous explicit scattering
result which contains the information of distance between target and observer.
We show that at a finite distance, a modification factor --- the Bessel
polynomial --- appears in the scattering amplitude, and, consequently, the
cross section depends on the distance, the outgoing wave-front surface is no
longer a sphere, and, besides the phase shift, there is an additional phase
(the argument of the Bessel polynomial) appears in the scattering wave
function
Matching Fully Differential NNLO Calculations and Parton Showers

We present a general method to match fully differential
next-to-next-to-leading (NNLO) calculations to parton shower programs. We
discuss in detail the perturbative accuracy criteria a complete NNLO+PS
matching has to satisfy. Our method is based on consistently improving a given
NNLO calculation with the leading-logarithmic (LL) resummation in a chosen jet
resolution variable. The resulting NNLO$+$LL calculation is cast in the form of
an event generator for physical events that can be directly interfaced with a
parton shower routine, and we give an explicit construction of the input "Monte
Carlo cross sections" satisfying all required criteria. We also show how other
proposed approaches naturally arise as special cases in our method.Comment: 53 pages, 3 figure
Bootstrapping the O(N) Vector Models

We study the conformal bootstrap for 3D CFTs with O(N) global symmetry. We
obtain rigorous upper bounds on the scaling dimensions of the first O(N)
singlet and symmetric tensor operators appearing in the $\phi_i \times \phi_j$
OPE, where $\phi_i$ is a fundamental of O(N). Comparing these bounds to
previous determinations of critical exponents in the O(N) vector models, we
find strong numerical evidence that the O(N) vector models saturate the
bootstrap constraints at all values of N. We also compute general lower bounds
on the central charge, giving numerical predictions for the values realized in
the O(N) vector models. We compare our predictions to previous computations in
the 1/N expansion, finding precise agreement at large values of N.Comment: 26 pages, 5 figures; V2: typos correcte
Particle-level pileup subtraction for jets and jet shapes

We present an extension to the jet area-based pileup subtraction for both jet
kinematics and jet shapes. A particle-level approach is explored whereby the
jet constituents are corrected or removed using an extension of the methods
currently being employed by the LHC experiments. Several jet shapes and nominal
jet radii are used to assess the performance in simulated events with pileup
levels equivalent to approximately 30 and 100 interactions per bunch crossing,
which are characteristic of both the LHC Run I and Run II conditions. An
improved performance in removing the pileup contributions is found when using
the new subtraction method. The performance of the new procedure is also
compared to other existing methods
Minimal Length, Friedmann Equations and Maximum Density

Inspired by Jacobson's thermodynamic approach[gr-qc/9504004], Cai et al
[hep-th/0501055,hep-th/0609128] have shown the emergence of Friedmann equations
from the first law of thermodynamics. We extend Akbar--Cai derivation
[hep-th/0609128] of Friedmann equations to accommodate a general entropy-area
law. Studying the resulted Friedmann equations using a specific entropy-area
law, which is motivated by the generalized uncertainty principle (GUP), reveals
the existence of a maximum energy density closed to Planck density. Allowing
for a general continuous pressure $p(\rho,a)$ leads to bounded curvature
invariants and a general nonsingular evolution. In this case, the maximum
energy density is reached in a finite time and there is no cosmological
evolution beyond this point which leaves the big bang singularity inaccessible
from a spacetime prospective. The existence of maximum energy density and a
general nonsingular evolution is independent of the equation of state and the
spacial curvature $k$. As an example we study the evolution of the equation of
state $p=\omega \rho$ through its phase-space diagram to show the existence of
a maximum energy which is reachable in a finite time.Comment: 15 pages, 1 figure, minor revisions, To appear in JHE
Cosmic acceleration with a negative cosmological constant in higher
  dimensions

We study gravitational theories with a cosmological constant and the
Gauss-Bonnet curvature squared term and analyze the possibility of de Sitter
expanding spacetime with a constant internal space. We find that there are two
branches of the de Sitter solutions: Both the curvature of the internal space
and the cosmological constant are (1) positive and (2) negative. From the
stability analysis, we show that the de Sitter solution of the case (1) is
unstable, while that in the case (2) is stable. Namely de Sitter solution in
the present system is stable if the cosmological constant is negative. We
extend our analysis to the gravitational theories with higher-order Lovelock
curvature terms. Although the existence and the stability of the de Sitter
solutions are very complicated and highly depend on the coupling constants,
there exist stable de Sitter solutions similar to the case (2). We also find de
Sitter solutions with Hubble scale much smaller than the scale of a
cosmological constant, which may explain a discrepancy between an inflation
energy scale and the Planck scale.Comment: 21 pages, 18 figures, v2: minor corrections, refs. added and typos
  correcte
A parton shower based on factorization of the quantum density matrix

We present first results from a new parton shower event generator, Deductor.
Anticipating a need for an improved treatment of parton color and spin, the
structure of the generator is based on the quantum density matrix in color and
spin space. So far, Deductor implements only a standard spin-averaged treatment
of spin in parton splittings. Although Deductor implements an improved
treatment of color, in this paper we present results in the standard leading
color approximation so that we can compare to the generator Pythia. The
algorithms used incorporate a virtuality based shower ordering parameter and
massive initial state bottom and charm quarks.Comment: 18 pages, 8 figure
Partition Functions in Even Dimensional AdS via Quasinormal Mode Methods

In this note, we calculate the one-loop determinant for a massive scalar
(with conformal dimension $\Delta$) in even-dimensional AdS$_{d+1}$ space,
using the quasinormal mode method developed in arXiv:0908.2657 by Denef,
Hartnoll, and Sachdev. Working first in two dimensions on the related Euclidean
hyperbolic plane $H_2$, we find a series of zero modes for negative real values
of $\Delta$ whose presence indicates a series of poles in the one-loop
partition function $Z(\Delta)$ in the $\Delta$ complex plane; these poles
contribute temperature-independent terms to the thermal AdS partition function
computed in arXiv:0908.2657. Our results match those in a series of papers by
Camporesi and Higuchi, as well as Gopakumar et.al. in arXiv:1103.3627 and
Banerjee et.al. in arXiv:1005.3044. We additionally examine the meaning of
these zero modes, finding that they Wick-rotate to quasinormal modes of the
AdS$_2$ black hole. They are also interpretable as matrix elements of the
discrete series representations of $SO(2,1)$ in the space of smooth functions
on $S^1$. We generalize our results to general even dimensional AdS$_{2n}$,
again finding a series of zero modes which are related to discrete series
representations of $SO(2n,1)$, the motion group of $H_{2n}$.Comment: 27 pages; v2: minor updates and JHEP versio
A Heterotic Standard Model with B-L Symmetry and a Stable Proton

We consider heterotic Calabi-Yau compactifications with S(U(4)xU(1))
background gauge fields. These models lead to gauge groups with an additional
U(1) factor which, under certain conditions, can combine with hypercharge to a
B-L symmetry. The associated gauge boson is automatically super-massive and,
hence, does not constitute a phenomenological problem. We illustrate this class
of compactifications with a model based on the monad construction, which leads
to a supersymmetric standard model with three families of quarks and leptons,
one pair of Higgs doublets, three right-handed neutrinos and no exotics charged
under the standard model group. The presence of the B-L symmetry means that the
model is safe from proton decay induced by dimension four operators. Due to the
presence of a special locus in moduli space where the bundle structure group is
Abelian and the low-energy symmetry enhances we can also show the absence of
dimension five proton-decay inducing operators.Comment: 23 pages Late
RG flows in 6D N=(1,0) SCFT from SO(4) half-maximal 7D gauged
  supergravity

We study $N=2$ seven-dimensional gauged supergravity coupled to three vector
multiplets with $SO(4)$ gauge group. The resulting gauged supergravity contains
10 scalars consisting of the dilaton and 9 vector multiplet scalars
parametrized by $SO(3,3)/SO(3)\times SO(3)$ coset manifold. The maximally
supersymmetric $AdS_7$ vacuum with unbroken $SO(4)$ symmetry is identified with
a $(1,0)$ SCFT in six dimensions. We find one new supersymmetric $AdS_7$
critical point preserving $SO(3)_{\textrm{diag}}\subset SO(3)\times SO(3)\sim
SO(4)$ and study a holographic RG flow interpolating between the $SO(4)$ and
the new $SO(3)$ supersymmetric critical points. The RG flow is driven by a
vacuum expectation value of a dimension-four operator and describes a
deformation of the UV $(1,0)$ SCFT to another supersymmetric fixed point in the
IR. In addition, a number of non-supersymmetric critical points are identified,
and some of them are stable with all scalar masses above the BF bound. RG flows
to non-conformal $N=(1,0)$ Super Yang-Mills with $SO(2)\times SO(2)$ and
$SO(2)$ symmetries are also investigated. Some of these flows have physically
acceptable IR singularities since the scalar potential is bounded above. These
provide physical RG flows from $(1,0)$ SCFT to non-conformal field theories in
six dimensions.Comment: 19 pages, no figures, more information added, typos and errors in
  flows to non-conformal theories correcte
CP violation from pure gauge in extra dimensions

One of the Sakharov's condition for baryogenesis is the violation of both C
and CP. In the Standard Model, gauge interactions break maximally C, but CP is
only broken through the Yukawa couplings in the poorly understood scalar
sector. In extra-dimensional models, extra components of gauge fields behave as
scalars in 4D and can acquire effective vev's through (finite) quantum effects
(Hosotani mechanism). This mechanism is used to build a toy model with 2
extra-dimensions compactified on a flat torus $T^2$, where a SU(2) gauge
symmetry is broken to U(1) and CP violation (in 4D) is expected. This is
verified by computing a non-vanishing electric dipole moment.Comment: 16 pages, 24 figures, final version accepted for publication in JHE
Step scaling and the Yang-Mills gradient flow

The use of the Yang-Mills gradient flow in step-scaling studies of lattice
QCD is expected to lead to results of unprecedented precision. Step scaling is
usually based on the Schr\"odinger functional, where time ranges over an
interval [0,T] and all fields satisfy Dirichlet boundary conditions at time 0
and T. In these calculations, potentially important sources of systematic
errors are boundary lattice effects and the infamous topology-freezing problem.
The latter is here shown to be absent if Neumann instead of Dirichlet boundary
conditions are imposed on the gauge field at time 0. Moreover, the expectation
values of gauge-invariant local fields at positive flow time (and of other well
localized observables) that reside in the center of the space-time volume are
found to be largely insensitive to the boundary lattice effects.Comment: Plain TeX source, 26 pages, 7 figures; v2: corrected typos and
  updated reference
Instability of rotating black holes: large D analysis

We study the stability of odd-dimensional rotating black holes with equal
angular momenta by performing an expansion in the inverse of the number of
dimensions D. Universality at large $D$ allows us to calculate analytically the
complex frequency of quasinormal modes to next-to-leading order in the
expansion. We identify the onset of non-axisymmetric, bar-mode instabilities at
a specific finite rotation, and axisymmetric instabilities at larger rotation.
The former occur at the threshold where the modes become superradiant, and
before the ultraspinning regime is reached. Our results fully confirm the
picture found in numerical studies, with very good quantitative agreement. We
extend the analysis to the same class of black holes in Anti-deSitter space,
and find the same qualitative features. We also discuss the appearance at high
frequencies of the universal set of (stable) quasinormal modes.Comment: 38 pages, 14 figures. v3: NLO results included so the instability is
  shown to occur before the ultraspinning regime of rotation. Significant
  improvements in accuracy. Ancillary Mathematica notebook contains details of
  NLO result
Twist-2 at five loops: Wrapping corrections without wrapping
  computations

Using known all-loop results from the BFKL and generalized double-logarithmic
equations and large spin limit we have recomputed the five-loop planar
anomalous dimension of twist-2 operators without consideration of any wrapping
effects. One part of the anomalous dimension was calculated in an usual way
with the help of Asymptotic Bethe Ansatz. The rest part, related with the
wrapping effects, was reconstructed from a known constraints with the help of
methods from the numbers theory.Comment: 23 pages, details added, typos correcte
Thermodynamics of Einstein-Proca AdS Black Holes

We study static spherically-symmetric solutions of the Einstein-Proca
equations in the presence of a negative cosmological constant. We show that the
theory admits solutions describing both black holes and also solitons in an
asymptotically AdS background. Interesting subtleties can arise in the
computation of the mass of the solutions and also in the derivation of the
first law of thermodynamics. We make use of holographic renormalisation in
order to calculate the mass, even in cases where the solutions have a rather
slow approach to the asymptotic AdS geometry. By using the procedure developed
by Wald, we derive the first law of thermodynamics for the black hole and
soliton solutions. This includes a non-trivial contribution associated with the
Proca "charge." The solutions cannot be found analytically, and so we make use
of numerical integration techniques to demonstrate their existence.Comment: 35 pages, Improved discussion of cases with logarithmic asymptotic
  fall off
Reconciling neutrino flux from heavy dark matter decay and recent events
  at IceCube

The IceCube detector has recently reported the observation of 28 events at
previously unexplored energies. While the statistics of the observed events are
still low, these events hint at the existence of a neutrino flux over and above
the atmospheric neutrino background. We investigate the possibility that a
significant component of the additional neutrino flux originates due to the
decay of a very heavy dark matter (VHDM) particle via several possible channels
into standard model particles. We show that a combination of a power law
astrophysical neutrino spectrum and the neutrino flux from the decay of a DM
species of mass in the range $150-400$ TeV improves the fit to the observed
neutrino events than that obtained from a best-fit astrophysical flux alone.
Assuming the existence of an astrophysical background described by the IC
best-fit, we also show that, for the decay of even heavier DM particles
($m_{\text{DM}} \sim 1$ PeV), the same observations impose significant
constraints on the decay lifetimes. Allowing the astrophysical flux
normalization to vary leads to modifications of these limits, however, there is
still a range of dark matter mass and lifetime that is excluded by the IC
results.Comment: v1: 8 pages, 2 figures, 2 tables. v2: Minimization over
  three-parameters (DM mass, lifetime and astrophysical power-law flux
  normalization); better statistical quantification of fit-goodness;
  conclusions unchanged; 15 pg, 3 figs, 2 tables; version to appear in JHE
Resolving the existence of Higgsinos in the LHC inverse problem

The LHC inverse problem is infamously challenging when neutralinos and
charginos are heavy and pure and other superparticles are decoupled. This limit
is becoming more relevant to particle physics nowadays. Fortunately, in this
limit, Higgsinos produce a distinctive signature if they are the LSPs or NLSPs.
The identifying signature is the presence of equal numbers of Z bosons and
Higgs bosons in NLSP productions and subsequent decays at hadron colliders. The
signature is derived from the Goldstone equivalence theorem by which partial
widths into Z and Higgs bosons are inherently related and from the fact that
Higgsinos consist of two indistinguishable neutralinos. Thus it is valid in
general for many supersymmetry models; exceptions may happen when Higgsino
NLSPs decay to weakly coupled LSPs such as axinos or gravitinos.Comment: 25 pages, 6 figures; v.2: published version with measurement
  prospects update