pinecone/core-2020-05-10-deduplication huggingface dataset:
Recursion Relations for Conformal Blocks

In the context of conformal field theories in general space-time dimension,
we find all the possible singularities of the conformal blocks as functions of
the scaling dimension $\Delta$ of the exchanged operator. In particular, we
argue, using representation theory of parabolic Verma modules, that in odd
spacetime dimension the singularities are only simple poles. We discuss how to
use this information to write recursion relations that determine the conformal
blocks. We first recover the recursion relation introduced in 1307.6856 for
conformal blocks of external scalar operators. We then generalize this
recursion relation for the conformal blocks associated to the four point
function of three scalar and one vector operator. Finally we specialize to the
case in which the vector operator is a conserved current.Comment: 55 pages, 12 figures; v2 Typos corrected, conclusions changed,
  reference adde
Small field inflation in ${\cal N}=1$ supergravity with a single chiral
  superfield

We consider "new inflation" inflationary models at small fields, embedded in
minimal ${\cal N}=1$ supergravity with a single chiral superfield. Imposing a
period of inflation compatible with experiment severely restricts possible
models, classified in perturbation theory. If moreover we impose that the field
goes to large values and very small potential at the current time, like would
be needed for instance for the inflaton being the volume modulus in large extra
dimensional scenarios, the possible models are restricted to very contrived
superpotentials.Comment: 25 pages, no figures; references and explanation adde
On Mirror Symmetry for Calabi-Yau Fourfolds with Three-Form Cohomology

We study the action of mirror symmetry on two-dimensional N=(2,2) effective
theories obtained by compactifying Type IIA string theory on Calabi-Yau
fourfolds. Our focus is on fourfold geometries with non-trivial three-form
cohomology. The couplings of the massless zero-modes arising by expanding in
these forms depend both on the complex structure deformations and the Kahler
structure deformations of the Calabi-Yau fourfold. We argue that two
holomorphic functions of the deformation moduli capture this information. These
are exchanged under mirror symmetry, which allows us to derive them at the
large complex structure and large volume point. We discuss the application of
the resulting explicit expression to F-theory compactifications and their weak
string coupling limit. In the latter orientifold settings we demonstrate
compatibility with mirror symmetry of Calabi-Yau threefolds at large complex
structure. As a byproduct we find an interesting relation of no-scale like
conditions on Kahler potentials to the existence of chiral and twisted-chiral
descriptions in two dimensions.Comment: 36 page
Syzygies Probing Scattering Amplitudes

We propose a new efficient algorithm to obtain the locally minimal generating
set of the syzygies for an ideal, i.e. a generating set whose proper subsets
cannot be generating sets. Syzygy is a concept widely used in the current study
of scattering amplitudes. This new algorithm can deal with more syzygies
effectively because a new generation of syzygies is obtained in each step and
the irreducibility of this generation is also verified in the process. This
efficient algorithm can also be applied in getting the syzygies for the
modules. We also show a typical example to illustrate the potential application
of this method in scattering amplitudes, especially the Integral-By-Part(IBP)
relations of the characteristic two-loop diagrams in the Yang-Mills theory.Comment: 33 pages, 10 figure
A new B-L model without right-handed neutrinos

We propose and study a novel extension of the Standard Model based on the B-L
gauge symmetry that can account for dark matter and neutrino masses. In this
model, right-handed neutrinos are absent and the gauge anomalies are canceled
instead by four chiral fermions with fractional B-L charges. After the breaking
of $U(1)_{B-L}$, these fermions arrange themselves into two Dirac particles,
the lightest of which is automatically stable and plays the role of the dark
matter. We determine the regions of the parameter space consistent with the
observed dark matter density and show that they can be partially probed via
direct and indirect dark matter detection or collider searches at the LHC.
Neutrino masses, on the other hand, can be explained by a variant of the
type-II seesaw mechanism involving one of the two scalar fields responsible for
the dark matter mass.Comment: 23 pages, 10 figure
Effective Field Theory of Dark Matter: a Global Analysis

We present global fits of an effective field theory description of real, and
complex scalar dark matter candidates. We simultaneously take into account all
possible dimension 6 operators consisting of dark matter bilinears and gauge
invariant combinations of quark and gluon fields. We derive constraints on the
free model parameters for both the real (five parameters) and complex (seven)
scalar dark matter models obtained by combining Planck data on the cosmic
microwave background, direct detection limits from LUX, and indirect detection
limits from the Fermi Large Area Telescope. We find that for real scalars
indirect dark matter searches disfavour a dark matter particle mass below 100
GeV. For the complex scalar dark matter particle current data have a limited
impact due to the presence of operators that lead to p-wave annihilation, and
also do not contribute to the spin-independent scattering cross- section.
Although current data are not informative enough to strongly constrain the
theory parameter space, we demonstrate the power of our formalism to
reconstruct the theoretical parameters compatible with an actual dark matter
detection, by assuming that the excess of gamma rays observed by the Fermi
Large Area Telescope towards the Galactic centre is entirely due to dark matter
annihilations. Please note that the excess can very well be due to
astrophysical sources such as millisecond pulsars. We find that scalar dark
matter interacting via effective field theory operators can in principle
explain the Galactic centre excess, but that such interpretation is in strong
tension with the non-detection of gamma rays from dwarf galaxies in the real
scalar case. In the complex scalar case there is enough freedom to relieve the
tension.Comment: 20 pages, 5 figure
The LPM effect in sequential bremsstrahlung 2: factorization

The splitting processes of bremsstrahlung and pair production in a medium are
coherent over large distances in the very high energy limit, which leads to a
suppression known as the Landau-Pomeranchuk-Migdal (LPM) effect. In this paper,
we continue analysis of the case when the coherence lengths of two consecutive
splitting processes overlap (which is important for understanding corrections
to standard treatments of the LPM effect in QCD), avoiding soft-gluon
approximations. In particular, this paper analyzes the subtle problem of how to
precisely separate overlapping double splitting (e.g.\ overlapping double
bremsstrahlung) from the case of consecutive, independent bremsstrahlung (which
is the case that would be implemented in a Monte Carlo simulation based solely
on single splitting rates). As an example of the method, we consider the rate
of real double gluon bremsstrahlung from an initial gluon with various
simplifying assumptions (thick media; $\hat q$ approximation; large $N_c$; and
neglect for the moment of processes involving 4-gluon vertices) and explicitly
compute the correction $\Delta\,d\Gamma/dx\,dy$ due to overlapping formation
times.Comment: 59 pages, 37 figures. The major changes from v1: new section I.A.4
  added to give kinetic theory analogy to better explain the importance of the
  subtraction defining Delta[d(Gamma)/dx dy]; new appendix F added to
  compare/contrast with issues raised by Blaizot, Dominguez, Iancu, and
  Mehtar-Tani [22
Two Higgs doublet models augmented by a scalar color octet

The LHC is now studying in detail the couplings of the Higgs boson in order
to determine if there is new physics. Many recent studies have examined the
available fits to Higgs couplings from the perspective of constraining two
Higgs doublet models (2HDM). In this paper we extend those studies to include
constraints on the one loop couplings of the Higgs to gluons and photons. These
couplings are particularly sensitive to the existence of new colored particles
that are hard to detect otherwise and we use them to constrain a 2HDM augmented
with a color-octet scalar, a possibility motivated by minimal flavor violation.
We first study theoretical constraints on this model and then compare them with
LHC measurements.Comment: 23 pages, 10 figures; Matched the publication versio
Stop searches in flavourful supersymmetry

Natural realisations of supersymmetry require light stops ${\tilde t}_1$,
making them a prime target of LHC searches for physics beyond the Standard
Model. Depending on the kinematic region, the main search channels are ${\tilde
t_1}\to t \tilde \chi^0_1$, ${\tilde t_1}\to W b \tilde \chi^0_1$ and ${\tilde
t_1}\to c \tilde \chi^0_1$. We first examine the interplay of these decay modes
with ${\tilde c_1}\to c \tilde \chi^0_1$ in a model-independent fashion,
revealing the existence of large regions in parameter space which are excluded
for any ${\tilde t_1}\to c \tilde \chi^0_1$ branching ratio. This effect is
then illustrated for scenarios with stop-scharm mixing in the right-handed
sector, where it has previously been observed that the stop mass limits can be
significantly weakened for large mixing. Our analysis shows that once the LHC
bounds from ${\tilde c_1}\to c \tilde \chi^0_1$ searches are taken into
account, non-zero stop-scharm mixing leads only to a modest increase in the
allowed regions of parameter space, with large areas excluded for arbitrary
mixing angles.Comment: 19 pages, 9 figure
Chaotic motion of particles in the accelerating and rotating black holes
  spacetime

We have investigated the motion of timelike particles along geodesic in the
background of accelerating and rotating black hole spacetime. We confirmed that
the chaos exists in the geodesic motion of the particles by Poincar\'e
sections, the power spectrum, the fast Lyapunov exponent indicator and the
bifurcation diagram. Moreover, we probe the effects of the acceleration and
rotation parameters on the chaotic behavior of a timelike geodesic particle in
the black hole spacetime. Our results show that the acceleration brings richer
physics for the geodesic motion of particles.Comment: 20 pages, 12 figures, Accepted by JHEP for publicatio
A new look at the theory uncertainty of epsilon_K

The observable epsilon_K is sensitive to flavor violation at some of the
highest scales. While its experimental uncertainty is at the half percent
level, the theoretical one is in the ballpark of 15%. We explore the nontrivial
dependence of the theory prediction and uncertainty on various conventions,
like the phase of the kaon fields. In particular, we show how such a rephasing
allows to make the short-distance contribution of the box diagram with two
charm quarks, eta_cc, purely real. Our results allow to slightly reduce the
total theoretical uncertainty of epsilon_K, while increasing the relative
impact of the imaginary part of the long distance contribution, underlining the
need to compute it reliably. We also give updated bounds on the new physics
operators that contribute to epsilon_K.Comment: 18 pages, 6 tables, 1 figure. v2: version accepted for publication on
  JHEP. v3: typos corrected, all results unchange
Bounds on the Conformal Scale of a Minimally Coupled Dilaton and
  Multi-Leptonic Signatures at the LHC

We explore the potential for the discovery of a dilaton
$\mathcal{O}(200-500)$ GeV in a classical scale/conformal invariant extension
of the Standard Model by investigating the size of the corresponding breaking
scale $\Lambda$ at the LHC, extending a previous analysis. In particular, we
address the recent bounds on $\Lambda$ derived from Higgs boson searches. We
investigate if such a dilaton can be produced via gluon-gluon fusion,
presenting rates for its decay either into a pair of Higgs bosons or into two
heavy gauge bosons, which can give rise to multi-leptonic final states. A
detailed analysis via PYTHIA-FastJet has been carried out of the dominant
Standard Model backgrounds, at a centre of mass energy of 14 TeV. We show that
early data of $\sim 20$ fb$^{-1}$ can certainly probe the region of parameter
space where such a dilaton is allowed. A conformal scale of 5 TeV is allowed by
the current data, for almost all values of the dilaton mass investigated.Comment: 26 pages, 37 figures and 7 tables, corrected final version to appear
  on JHE
String Theory as a Higher Spin Theory

The symmetries of string theory on ${\rm AdS}_3 \times {\rm S}^3 \times
\mathbb{T}^4$ at the dual of the symmetric product orbifold point are described
by a so-called Higher Spin Square (HSS). We show that the massive string
spectrum in this background organises itself in terms of representations of
this HSS, just as the matter in a conventional higher spin theory does so in
terms of representations of the higher spin algebra. In particular, the entire
untwisted sector of the orbifold can be viewed as the Fock space built out of
the multiparticle states of a single representation of the HSS, the so-called
`minimal' representation. The states in the twisted sector can be described in
terms of tensor products of a novel family of representations that are somewhat
larger than the minimal one.Comment: 34 pages; v2: typos fixe
Nambu-Goldstone Boson Hypothesis for Squarks and Sleptons in Pure
  Gravity Mediation

We point out that a hypothesis of squarks and sleptons being Nambu-Goldstone
(NG) bosons is consistent with pure gravity mediation or minimal split
supersymmetry (SUSY). As a concrete example, we consider a SUSY $E_7/SU(5)
\times U(1)^3$ non-linear sigma model in the framework of pure gravity
mediation. The model accommodates three families of the quark and lepton chiral
multiplets as (pseudo) NG multiplets of the Kahler manifold, which may enable
us to understand the origin and number of the families. We point out that
squarks in the first and second generations are likely to be as light as a few
TeV if the observed baryon asymmetry is explained by the thermal leptogenesis;
therefore, these colored particles can be discovered at the LHC Run-2 or at the
high luminosity LHC.Comment: 18 pages, 7 figure
The QCD phase diagram in the limit of heavy quarks using complex
  Langevin dynamics

Complex Langevin simulations allow numerical studies of theories that exhibit
a sign problem, such as QCD, and are thereby potentially suitable to determine
the QCD phase diagram from first principles. Here we study QCD in the limit of
heavy quarks for a wide range of temperatures and chemical potentials. Our
results include an analysis of the adaptive gauge cooling technique, which
prevents large excursions into the non-compact directions of the SL($3,
\mathbb{C}$) manifold. We find that such excursions may appear spontaneously
and change the statistical distribution of physical observables, which leads to
disagreement with known results. Results whose excursions are sufficiently
small are used to map the boundary line between confined and deconfined quark
phases.Comment: 18 pages, 10 figures, accepted for publication in JHE
Duality invariance in Fayet-Iliopoulos gauged supergravity

We propose a geometric method to study the residual symmetries in $N=2$,
$d=4$ $\text{U}(1)$ Fayet-Iliopoulos (FI) gauged supergravity. It essentially
involves the stabilization of the symplectic vector of gauge couplings (FI
parameters) under the action of the U-duality symmetry of the ungauged theory.
In particular we are interested in those transformations that act non-trivially
on the solutions and produce scalar hair and dyonic black holes from a given
seed. We illustrate the procedure for finding this group in general and then
show how it works in some specific models. For the prepotential $F=-iX^0X^1$,
we use our method to add one more parameter to the rotating Chow-Comp\`ere
solution, representing scalar hair.Comment: 31 pages, uses jheppub.sty. Final version to appear on JHE
A magnetically induced quantum phase transition in holography

We investigate quantum phase transitions in a 2+1 dimensional gauge theory at
finite chemical potential $\chi$ and magnetic field $B$. The gravity dual is
based on 4D $\mathcal{N}=2$ Fayet-Iliopoulos gauged supergravity and the
solutions we consider---that are constructed analytically---are extremal,
dyonic, asymptotically $AdS_4$ black-branes with a nontrivial radial profile
for the scalar field. We discover a line of second order fixed points at
$B=B_c(\chi)$ between the dyonic black brane and an extremal "thermal gas"
solution with a singularity of good-type, according to the acceptability
criteria of Gubser [1]. The dual field theory is the ABJM theory [2] deformed
by a triple trace operator $\Phi^3$ and placed at finite charge and magnetic
field. This line of fixed points might be useful in studying the various
strongly interacting quantum critical phenomena such as the ones proposed to
underlie the cuprate superconductors. We also find curious similarities between
the behaviour of the VeV $\langle \Phi \rangle$ under B and that of the quark
condensate in 2+1 dimensional NJL models.Comment: 33 pages, 7 figure
Two-Loop Master Integrals for the mixed EW-QCD virtual corrections to
  Drell-Yan scattering

We present the calculation of the master integrals needed for the two-loop
QCDxEW corrections to $ q + \bar{q} \to l^- + l^+$ and $ q + \bar{q}' \to l^- +
\overline{\nu} \, , $ for massless external particles. We treat W and Z bosons
as degenerate in mass. We identify three types of diagrams, according to the
presence of massive internal lines: the no-mass type, the one-mass type, and
the two-mass type, where all massive propagators, when occurring, contain the
same mass value. We find a basis of 49 master integrals and evaluate them with
the method of the differential equations. The Magnus exponential is employed to
choose a set of master integrals that obeys a canonical system of differential
equations. Boundary conditions are found either by matching the solutions onto
simpler integrals in special kinematic configurations, or by requiring the
regularity of the solution at pseudo-thresholds. The canonical master integrals
are finally given as Taylor series around d=4 space-time dimensions, up to
order four, with coefficients given in terms of iterated integrals,
respectively up to weight four.Comment: 1+45 pages, 6 figures, 1 table, 5 ancillary file
Covariant effective action for a Galilean invariant quantum Hall system

We construct effective field theories for gapped quantum Hall systems coupled
to background geometries with local Galilean invariance i.e. Bargmann
spacetimes. Along with an electromagnetic field, these backgrounds include the
effects of curved Galilean spacetimes, including torsion and a gravitational
field, allowing us to study charge, energy, stress and mass currents within a
unified framework. A shift symmetry specific to single constituent theories
constraints the effective action to couple to an effective background gauge
field and spin connection that is solved for by a self-consistent equation,
providing a manifestly covariant extension of Hoyos and Son's improvement terms
to arbitrary order in $m$.Comment: v2: updated version published in JHEP; v1: 25 pages + Appendi
Anatomy of Exotic Higgs Decays in 2HDM

Large mass splittings between new scalars in two-Higgs-doublet models (2HDM)
open a key avenue to search for these new states via exotic heavy Higgs decays.
We discuss in detail the different search channels for these new scalars at the
LHC in the presence of a sizable mass splitting, i.e. a hierarchical 2HDM
scenario, taking into account the theoretical and experimental constraints. We
provide benchmark planes to exploit the complementarity among these searches,
analyzing their potential to probe the hierarchical 2HDM parameter space during
LHC Run 2
Manifesting Color-Kinematics Duality in the Scattering Equation
  Formalism

We prove that the scattering equation formalism for Yang-Mills amplitudes can
be used to make manifest the theory's color-kinematics duality. This is
achieved through a concrete reduction algorithm which renders this duality
manifest term-by-term. The reduction follows from the recently derived set of
identities for amplitudes expressed in the scattering equation formalism that
are analogous to monodromy relations in string theory. A byproduct of our
algorithm is a generalization of the identities among gravity and Yang-Mills
amplitudes.Comment: 20 pages, 20 figure
Level/rank Duality and Chern-Simons-Matter Theories

We discuss in detail level/rank duality in three-dimensional Chern-Simons
theories and various related dualities in three-dimensional Chern-Simons-matter
theories. We couple the dual Lagrangians to appropriate background fields
(including gauge fields, spin$_c$ connections and the metric). The non-trivial
maps between the currents and the line operators in the dual theories is
accounted for by mixing of these fields. In order for the duality to be valid
we must add finite counterterms depending on these background fields. This
analysis allows us to resolve a number of puzzles with these dualities, to
provide derivations of some of them, and to find new consistency conditions and
relations between them. In addition, we find new level/rank dualities of
topological Chern-Simons theories and new dualities of Chern-Simons-matter
theories, including new boson/boson and fermion/fermion dualities.Comment: 36 pages, clarifications about the fixed point with several flavor
Nonthermal production of dark radiation and dark matter

Dark matter may be coupled to dark radiation: light degrees of freedom that
mediate forces between dark sector particles. Cosmological constraints favor
dark radiation that is colder than Standard Model radiation. In models with
fixed couplings between dark matter and the Standard Model, these constraints
can be difficult to satisfy if thermal equilibrium is assumed in the early
universe. We construct a model of asymmetric reheating of the visible and dark
sectors from late decays of a long-lived particle (for instance, a modulus). We
show, as a proof-of-principle, that such a model can populate a sufficiently
cold dark sector while also generating baryon and dark matter asymmetries
through the out of equilibrium decay. We frame much of our discussion in terms
of the scenario of dissipative dark matter, as in the Double-Disk Dark Matter
scenario. However, our results may also be of interest for other scenarios like
the Twin Higgs model that are in danger of overproducing dark radiation due to
nonnegligible dark-visible couplings.Comment: v2: accepted by JHEP; added discussion of baryon violation
  constraints, some correction
Supersymmetric Adler Functions and Holography

We perform several tests on a recent proposal by Shifman and Stepanyantz for
an exact expression for the current correlation functions in supersymmetric
gauge theories. We clarify the meaning of the relation in superconformal
theories. In particular we show that it automatically follows from known
relations between the current correlation functions and anomalies. It therefore
also automatically matches between different dual realizations of the same
superconformal theory. We use holographic examples as well as calculations in
free theories to show that the proposed relation fails in theories with mass
terms.Comment: 13 page