pinecone/core-2020-05-10-deduplication huggingface dataset:
The enhanced holographic superconductor: is it possible?

It is known that time-dependent perturbations can enhance superconductivity
and increase the critical temperature. If this phenomenon happens to high-T_c
superconductors, one could obtain room-temperature superconductors, but this is
still an open issue experimentally. Meanwhile, we would like to understand this
phenomenon from gravity dual and see if the enhancement is possible for
holographic superconductors. Previous work (arXiv:1104.4098 [hep-th]) has
studied this issue by adding a "time-dependent chemical potential," but their
analysis is questionable as a true dynamic equilibrium. In particular, the AdS
boundary does not supply energy to the bulk spacetime in their setup. A more
appropriate way to discuss the enhancement is to add a time-dependent vector
potential, i.e., a time-dependent electric field. However, the enhancement does
not occur for holographic superconductors.Comment: 26 pages, 3 figures, JHEP; v2: added comment in Sec. 4.3 to the
  published version (v1
Superradiant instability of Kerr-de Sitter black holes in scalar-tensor
  theory

We investigate in detail the mechanism of superradiance to render the
instability of Kerr-de Sitter black holes in scalar-tensor gravity. Our results
provide more clues to examine the scalar-tensor gravity in the astrophysical
black holes in the universe with cosmological constant. We also discuss the
spontaneous scalarization in the de Sitter background and find that this
instability can also happen in the spherical de Sitter configuration in a
special style.Comment: (v2)21 pages, 21 figures; Sec. V revised; This version has been
  accepted for publication by JHE
Weak Scale Baryogenesis in a Supersymmetric Scenario with R-parity
  violation

We investigate the connection between R-parity violation (RPV) in
supersymmetric models and Baryogenesis. First we discuss in detail the
assumptions of a theorem by Nanopoulos and Weinberg on the CP asymmetry
generated from the decay of massive particles. In light of this statement, we
analyse some interesting models of Baryogenesis through RPV. We then explore,
in the context of RPV SUSY, the possibility to generate the baryon asymmetry
through the out-of-equilibrium decay of a metastable Weakly Interacting Massive
Particle (WIMP), as proposed in \cite{Cui:2012jh}. This setting is also
motivated by the observed coincidence between the abundances of dark and
baryonic matter. In this framework, we propose two models of out-of-equilibrium
decay of a would-be cold relic, and compute the associated CP asymmetry. With a
TeV-scale parent, the observed baryon abundance can be reproduced in these
models when the stop is in the multi-TeV region. Furthermore, annihilation of
the metastable particle into SM states must be characterised by a very weak
coupling, $g\sim 10^{-2}$ and by a heavy mediator $m_{med}\sim 10$ TeV. These
models can also accommodate stop masses far from the TeV scale, at the expense
of weakening the explanation of the $\Omega_{B}-\Omega_{DM}$ coincidence.Comment: 31 pages, 12 figures. Revised version according to JHEP requirements:
  quantitative analyses added in Sec. 4, extended and revised list of refs,
  abstract and conclusions clarifie
Dark matter versus h → γγ and h → γ Z with supersymmetric triplets

The Triplet extension of the MSSM (TMSSM) alleviates the little hierarchy problem and provides a significant enhancement of the loop-induced diphoton rate of the lightest CP-even Higgs h . In this paper we pursue the analysis of the TMSSM Higgs phenomenology by computing for the first time the h → Z γ decay. Interestingly we find that the rates of loop-induced decays are correlated and their signal strengths can rise up to 40%-60% depending on the channel. We furthermore study the dark matter phenomenology of the TMSSM. The lightest neutralino is a good dark matter candidate in two regions. The first one is related to the Higgs and Z resonances and the LSP is mostly Bino. The second one is achieved for a mass larger than 90 GeV and the LSP behaves as the well-tempered neutralino. An advantage of the triplet contribution is that the well-tempered neutralino can be a Bino-Triplino mixture, relieving the problem of achieving M 2 ~ M 1 in unified scenarios. The dark matter constraints strongly affect the Higgs phenomenology, reducing the potential enhancements of the diphoton and of the Z γ channels by 20% at most. In the near future, dark matter direct searches and collider experiments will probe most of the parameter space where the neutralino is the dark matter candidate
Comments on scale and conformal invariance

There has been recent interest in the question of whether four dimensional scale invariant unitary quantum field theories are actually conformally invariant. In this note we present a complete analysis of possible scale anomalies in correlation functions of the trace of the stress-energy tensor in such theories. We find that 2-, 3- and 4-point functions have a non-trivial anomaly while connected higher point functions are non-anomalous. We pay special attention to semi-local contributions to correlators (terms with support on a set containing both coincident and separated points) and show that the anomalies in 3- and 4-point functions can be accounted for by such contributions. We discuss the implications of the our results for the question of scale versus conformal invariance
NNLO QCD subtraction for top-antitop production in the $q\bar{q}$ channel

We present the computation of the double real and real-virtual contributions to top-antitop pair production in the quark-antiquark channel at leading colour. The TeX → TeX amplitudes contributing to the real-virtual part are computed with OpenLoops, and their numerical stability in the soft and collinear regions is found to be sufficiently high to perform a realistic NNLO calculation in double precision. The subtraction terms required at real-real and real-virtual levels are constructed within the antenna subtraction formalism extended to deal with the presence of coloured massive final state particles. We show that those subtraction terms approximate the real-real and real-virtual matrix elements in all their singular limits
The gravity dual of supersymmetric gauge theories on a squashed S 1 × S 3

We present a new one-parameter family of supersymmetric solutions deforming AdS 5 . This is constructed as an asymptotically locally anti de Sitter (AlAdS) solution of five-dimensional minimal gauged supergravity, with topology ℝ × ℝ 4 and a non-trivial graviphoton field, and can be uplifted to ten or eleven dimensional supergravities. An analytic continuation of this solution yields the gravity dual to a class of four-dimensional N = 1 $$ \mathcal{N}=1 $$ supersymmetric gauge theories on a curved manifold with topology S 1 × S 3 , comprising an SU(2) × U(1)-symmetric squashed three-sphere, with a non-trivial background gauge field coupling to the R-symmetry current. We compute the holographically renormalised on-shell action and interpret it in terms of the Casimir energy of the dual field theory. We also determine the holographic conserved charges of the solution and discuss relations between them
Large field inflation and double α -attractors

We consider a broad class of inflationary models that arise naturally in super-gravity. They are defined in terms of a parameter α that determines the curvature and cutoff of these models. As a function of this parameter, we exhibit that the inflationary predictions generically interpolate between two attractor points. At small cutoff α , the resulting inflationary model is of plateau-type with n s = 1 − 2 /N and r = 12 α/N 2 . For α = 1, these predictions coincide with predictions of the Starobinsky model and Higgs inflation. In contrast, for large cutoff α , the theory asymptotes to quadratic inflation, with n s = 1 − 2 /N , r = 8 /N . Both universal predictions can be attributed to a stretching of the moduli space. For intermediate values of α , the predictions interpolate between these two critical points, thus covering the sweet spots of both Planck and BICEP2
Subleading Soft Factor for String Disk Amplitudes

We investigate the behavior of superstring disk scattering amplitudes in the
presence of a soft external momentum at finite string tension. We prove that
there are no $\alpha'$-corrections to the field theory form of the subleading
soft factor $S^{(1)}$. At the end of this work, we also comment on the
possibility to find the corresponding subleading soft factors in closed string
theory using our result and the KLT relations.Comment: 15 pages, v2: minor changes, new references, version accepted by JHE
Hadroproduction of $W^+ W^- b \bar{b}$ at NLO accuracy matched with
  shower Monte Carlo programs

We present the computation of the differential cross section for the process
$pp(\bar{p}) \to (W^+\,W^-\,b\,\bar{b}
\to)\;e^+\,\nu_e\,\mu^-\,\bar{\nu}_\mu\,b\, \bar{b}+X$ at NLO QCD accuracy
matched to Shower Monte Carlo (SMC) simulations using PowHel, on the basis of
the interface between HELAC-NLO and POWHEG-BOX. We include all resonant and
non-resonant contributions. This is achieved by fully taking into account the
effect of off-shell t-quarks and off-shell W-bosons in the complex mass scheme.
We also present a program called DECAYER that can be used to let the t-quarks
present in the event files for $pp(\bar{p}) \to {t\,\bar{t}\,X}$ processes
decay including both the finite width of the t-quarks and spin correlations. We
present predictions for both the Tevatron and the LHC, with emphasis on
differences emerging from three different $W^+\,W^-\,b\,\bar{b}$
hadroproduction computations: (i) full implementation of the $p\,p(\bar{p}) \to
W^+\,W^-\,b\,\bar{b}$ process, (ii) generating on-shell t-quarks pushed
off-shell with a Breit-Wigner finite width and decayed by DECAYER, and (iii)
on-shell t-quark production followed by decay in the narrow width
approximation, as described by the SMC.Comment: 40 pages, 26 figures; slightly expanded version matching the one
  published in JHE
Graviton propagation in an asymmetric warped background: Lorentz violation and the null energy condition

The graviton propagation in an asymmetric background is studied. The background is a configuration in the six-dimensional Salam-Sezgin model, in which a 3-form H-field turned on [ JHEP 0910 (2009) 086]. The compact dimensions form a cylindrical space with branes as boundaries. The background gets asymmetry due to the H-field and violates the Lorentz symmetry. We derive the graviton equation in this background and show that it gets massless mode traveling with superluminal speed. A tower of K-K modes exists with a mass gap. On the other hand, it is known that breaking the Lorentz symmetry on an asymmetric background is constrained by the null energy condition. This no-go theorem doesn’t work well in six-dimensional space-times and by this model we provide a counterexample for which the null energy condition is satisfied while the Lorentz symmetry is gravitationally violated
The Continuous Orbifold of N=2 Minimal Model Holography

For the N=2 Kazama-Suzuki models that appear in the duality with a higher
spin theory on AdS_3 it is shown that the large level limit can be interpreted
as a continuous orbifold of 2N free bosons and fermions by the group U(N). In
particular, we show that the subset of coset representations that correspond to
the perturbative higher spin degrees of freedom are precisely described by the
untwisted sector of this U(N) orbifold. We furthermore identify the twisted
sector ground states of the orbifold with specific coset representations, and
give various pieces of evidence in favour of this identification.Comment: 24 pages, v2: minor correction
Higher Poles and Crossing Phenomena from Twisted Genera

We demonstrate that Appell-Lerch sums with higher order poles as well as
their modular covariant completions arise as partition functions in the cigar
conformal field theory with worldsheet supersymmetry. The modular covariant
derivatives of the elliptic genus of the cigar give rise to operator insertions
corresponding to (powers of) right-moving momentum, left-moving fermion number,
as well as a term corresponding to an ordinary zero mode partition sum. To show
this, we demonstrate how the right-moving supersymmetric quantum mechanics (and
in particular the Hamiltonian and spectral density) depend on the imaginary
part of the chemical potential for angular momentum. As a consequence of our
analysis we find that varying the imaginary part of the chemical potential for
angular momentum on the cigar gives rise to a wall-crossing phenomenon in the
bound state contribution to the elliptic genus, while the full elliptic genus
is a continuous function of the chemical potential.Comment: 29 page
Effective Lagrangians for quantum many-body systems

The low-energy and low-momentum dynamics of systems with a spontaneously
broken continuous symmetry is dominated by the ensuing Nambu-Goldstone bosons.
It can be conveniently encoded in a model-independent effective field theory
whose structure is fixed by symmetry up to a set of effective coupling
constants. We construct the most general effective Lagrangian for the
Nambu-Goldstone bosons of spontaneously broken global internal symmetry up to
the fourth order in derivatives. Rotational invariance and spatial
dimensionality of one, two or three are assumed in order to obtain compact
explicit expressions, but our method is completely general and can be applied
without modifications to condensed matter systems with a discrete space group
as well as to higher-dimensional theories. The general low-energy effective
Lagrangian for relativistic systems follows as a special case. We also discuss
the effects of explicit symmetry breaking and classify the corresponding terms
in the Lagrangian. Diverse examples are worked out in order to make the results
accessible to a wide theoretical physics community.Comment: 45 page
TMD PDFs in the Laguerre polynomial basis

We suggest the modified matching procedure for TMD PDF to the integrated PDF
aimed to increase the amount of perturbative information in the TMD PDF
expression. The procedure consists in the selection and usage of the
non-minimal operator basis, which restricts the expansion to desired general
behavior. The implication of OPE allows to systematic account of the higher
order corrections. In the case of TMD PDF we assume the Gaussian behavior,
which suggests Laguerre polynomial basis as the best for the convergence of
OPE. We present the leading and next-to-leading expression of TMD PDF in this
basis. The obtained perturbative expression for the TMD PDF is valid in the
wide region of $b_T$ (we estimate this region as $b_T\lesssim 2-3$ GeV$^{-1}$
depending on $x$).Comment: 19 pages, 6 figures; corrected abstract, conclusion and various
  misprints; version submitted to JHE
Constraints on the Path-Length Dependence of Jet Quenching in Nuclear
  Collisions at RHIC and LHC

Recent data on the high-pT pion nuclear modification factor, $R_{AA}(p_T)$,
and its elliptic azimuthal asymmetry, $v_2(p_T)$, from RHIC/BNL and LHC/CERN
are analyzed in terms of a wide class of jet-energy loss models coupled to
different (2+1)d transverse plus Bjorken expanding hydrodynamic fields. We test
the consistency of each model by demanding a simultaneous account of the
azimuthal, the transverse momentum, and the centrality dependence of the data
at both 0.2 and 2.76 ATeV energies. We find a rather broad class of jet-energy
independent energy-loss models $dE/dx= \kappa(T) x^z T^{2+z} \zeta_q$ that,
when coupled to bulk constrained temperature fields T(x,t), can account for the
current data at the $\chi^2<2$ level with different temperature-dependent
jet-medium couplings and path-length dependence exponents $0\le z \le 2$. We
test the sensitivity of predictions to different skewed energy-loss
fluctuations via a convenient scaling factor distributed in a finite range $0<
\zeta_q < 2+q$ with unit mean. While a previously proposed AdS/CFT jet-energy
loss model with a temperature-independent jet-medium coupling as well as a
near-$T_c$ dominated, pQCD-inspired energy-loss scenario are shown to be
inconsistent with the LHC data, once the parameters are constrained by fitting
to RHIC results, we find several new solutions with a temperature-dependent
jet-medium coupling. We conclude that the current level of statistical and
systematic uncertainties of the measured data does not allow a constraint on
the path-length exponent z to a range narrower than [0-2].Comment: 23 pages, 13 figues, 3 tables; figures 4 and 9 corrected, main
  conclusions remain unchange
On symmetries of N=(4,4) sigma models on T^4

Motivated by an analogous result for K3 models, we classify all groups of
symmetries of non-linear sigma models on a torus T^4 that preserve the N=(4,4)
superconformal algebra. The resulting symmetry groups are isomorphic to certain
subgroups of the Weyl group of E8, that plays a role similar to the Conway
group for the case of K3 models. Our analysis heavily relies on the triality
automorphism of the T-duality group SO(4,4,Z). As a byproduct of our results,
we discover new explicit descriptions of K3 models as asymmetric orbifolds of
torus CFTs.Comment: 42 pages; minor changes, references added; version accepted for
  publicatio
The NSVZ beta-function and the Schwinger-Dyson equations for N=1 SQED
  with N_f flavors, regularized by higher derivatives

The effective diagram technique based on the Schwinger-Dyson equations is
constructed for N=1 SQED with N_f flavors, regularized by higher derivatives.
Using these effective diagrams, it is possible to derive the exact NSVZ
relation between the beta-function and the anomalous dimension of the matter
superfields exactly in all loops, if the renormalization group functions are
defined in terms of the bare coupling constant. In particular, we verify that
all integrals which give the beta-function defined in terms of the bare
coupling constant are integrals of double total derivatives and prove some
identities relating Green functions.Comment: 70 pages, 24 figures; v2: a reference adde
AdS 3 × S 3 × M 4 string S-matrices from unitarity cuts

Continuing the program initiated in arXiv:1304.1798 we investigate unitarity methods applied to two-dimensional integrable field theories. The one-loop computation is generalized to encompass theories with different masses in the asymptotic spectrum and external leg corrections. Additionally, the prescription for working with potentially singular cuts is modified to cope with an ambiguity that was not encountered before. The resulting methods are then applied to three light-cone gauge string theories; i) AdS 3 × S 3 × T 4 supported by RR flux, ii) AdS 3 × S 3 × S 3 × S 1 supported by RR flux and iii) AdS 3 × S 3 × T 4 supported by a mix of RR and NSNS fluxes. In the first case we find agreement with the exact result following from symmetry considerations and in the second case with one-loop semiclassical computations. This agreement crucially includes the rational terms and hence supports the conjecture that S-matrices of integrable field theories are cut-constructible, up to a possible shift in the coupling. In the final case, under the assumption that our methods continue to give all rational terms, we give a conjecture for the one-loop phases
Ω-deformation and quantization

We formulate a deformation of Rozansky-Witten theory analogous to the Ω-deformation. It is applicable when the target space X is hyperkähler and the spacetime is of the form ℝ×Σ, with Σ being a Riemann surface. In the case that Σ is a disk, the Ω-deformed Rozansky-Witten theory quantizes a symplectic submanifold of X , thereby providing a new perspective on quantization. As applications, we elucidate two phenomena in four- dimensional gauge theory from this point of view. One is a correspondence between the Ω-deformation and quantization of integrable systems. The other concerns supersymmetric loop operators and quantization of the algebra of holomorphic functions on a hyperkähler manifold
The Fermionic Dark Matter Higgs Portal: an effective field theory
  approach

We consider fermionic (Dirac or Majorana) cold thermal relic dark-matter
coupling to standard-model particles through the effective dimension-5 Higgs
portal operators $\Lambda^{-1} \ \mathcal{O}_{\text{DM}} \cdot H^\dagger H$,
where $\mathcal{O}_{\text{DM}}$ is an admixture of scalar $\bar\chi\chi$ and
pseudoscalar $\bar\chi i\gamma_5 \chi$ DM operators. Utilizing the relic
abundance requirement to fix the couplings, we consider direct detection and
invisible Higgs width constraints, and map out the remaining allowed parameter
space of dark-matter mass and the admixture of scalar and pseudoscalar
couplings. We emphasize a subtlety which has not previously been carefully
studied in the context of the EFT approach, in which an effect arising due to
electroweak symmetry breaking can cause a na\"ively pure pseudoscalar coupling
to induce a scalar coupling at higher order, which has important implications
for direct detection bounds. We provide some comments on indirect detection
bounds and collider searches.Comment: 22 pages, 8 figures. Published versio
New physics in e + e − → Z γ at the ILC with polarized beams: explorations beyond conventional anomalous triple gauge boson couplings

One of the most-studied signals for physics beyond the standard model in the production of gauge bosons in electron-positron collisions is due to the anomalous triple gauge boson couplings in the Z γ final state. In this work, we study the implications of this at the ILC with polarized beams for signals that go beyond traditional anomalous triple neutral gauge boson couplings. Here we report a dimension-8 CP-conserving Z γ Z vertex that has not found mention in the literature. We carry out a systematic study of the anomalous couplings in general terms and arrive at a classification. We then obtain linear-order distributions with and without CP violation. Furthermore, we place the study in the context of general BSM interactions represented by e + e − Z γ contact interactions. We set up a correspondence between the triple gauge boson couplings and the four-point contact interactions. We also present sensitivities on these anomalous couplings, which will be achievable at the ILC with realistic polarization and luminosity
Covariant approaches to superconformal blocks

We develop techniques for computing superconformal blocks in 4d superconformal field theories. First we study the super-Casimir differential equation, deriving simple new expressions for superconformal blocks for 4-point functions containing chiral operators in theories with N $$ \mathcal{N} $$ -extended supersymmetry. We also reproduce these results by extending the “shadow formalism” of Ferrara, Gatto, Grillo, and Parisi to supersymmetric theories, where superconformal blocks can be represented as superspace integrals of three-point functions multiplied by shadow three-point functions