pinecone/core-2020-05-10-deduplication huggingface dataset:
Probing gluon saturation with next-to-leading order photon production at
  central rapidities in proton-nucleus collisions

We compute the cross section for photons emitted from sea quarks in
proton-nucleus collisions at collider energies. The computation is performed
within the dilute-dense kinematics of the Color Glass Condensate (CGC)
effective field theory. Albeit the result obtained is formally at
next-to-leading order in the CGC power counting, it provides the dominant
contribution for central rapidities. We observe that the inclusive photon cross
section is proportional to all-twist Wilson line correlators in the nucleus.
These correlators also appear in quark-pair production; unlike the latter,
photon production is insensitive to hadronization uncertainties and therefore
more sensitive to multi-parton correlations in the gluon saturation regime of
QCD. We demonstrate that $k_\perp$ and collinear factorized expressions for
inclusive photon production are obtained as leading twist approximations to our
result. In particular, the collinearly factorized expression is directly
sensitive to the nuclear gluon distribution at small $x$. Other results of
interest include the realization of the Low-Burnett-Kroll soft photon theorem
in the CGC framework and a comparative study of how the photon amplitude is
obtained in Lorenz and light-cone gauges.Comment: 28 pages, 7 figures, a few points clarified, typos corrected, matches
  the version accepted for publicatio
Perturbations of spiky strings in flat spacetimes

Perturbations of a class of semiclassical strings known today as spiky
strings, are studied using the well-known Jacobi equations for small normal
deformations of an embedded timelike surface. It is shown that there exists
finite normal perturbations of the spiky string worldsheets embedded in a $2+1$
dimensional flat spacetime. Such perturbations lead to a rounding off of the
spikes, which, in a way, demonstrates the stable nature of the unperturbed
worldsheet. The same features appear for the dual spiky string solution and in
the spiky as well as their dual solutions in $3+1$ dimensional flat spacetime.
Our results are based on exact solutions of the corresponding Jacobi equations
which we obtain and use while constructing the profiles of the perturbed
configurations.Comment: 23 pages, 19 figures, added definitions and clarifications, minor
  changes, to appear in JHE
Fluid/gravity correspondence: Second order transport coefficients in
  compactified D4-branes

We develop the boundary derivative expansion (BDE) formalism of fluid/gravity
correspondence to nonconformal version through the compactified, near-extremal
black D4-brane. We offer an explicit calculation of 9 second order transport
coefficients, i.e., the $\tau_\pi,~\tau_\pi^*,~\tau_\Pi,~\lambda_{1,2,3}$ and
$\xi_{1,2,3}$ for the strongly coupled, uncharged and nonconformal relativistic
fluid which is the holographic dual of compactified, near extremal black
D4-brane. We also show that the nonconformal fluid considered in this work is
free of causal problem and admits the Haack-Yarom relation
$4\lambda_1+\lambda_2=2\eta\tau_\pi$.Comment: 41 pages and 4 table
Holomorphic Yukawa Couplings for Complete Intersection Calabi-Yau
  Manifolds

We develop methods to compute holomorphic Yukawa couplings for heterotic
compactifications on complete intersection Calabi-Yau manifolds, generalising
results of an earlier paper for Calabi-Yau hypersurfaces. Our methods are based
on constructing the required bundle-valued forms explicitly and evaluating the
relevant integrals over the projective ambient space. We also show how our
approach relates to an earlier, algebraic one to calculate the holomorphic
Yukawa couplings. A vanishing theorem, which we prove, implies that certain
Yukawa couplings allowed by low-energy symmetries are zero due to topological
reasons. To illustrate our methods, we calculate Yukawa couplings for
SU(5)-based standard models on a co-dimension two complete intersection
manifold.Comment: 40 pages, Latex; v2: minor corrections, references adde
Bootstrap equations for $\mathcal{N}=4$ SYM with defects

This paper focuses on the analysis of $4d$ $\mathcal{N}=4$ superconformal
theories in the presence of a defect from the point of view of the conformal
bootstrap. We will concentrate first on the case of codimension one, where the
defect is a boundary that preserves half of the supersymmetry. After studying
the constraints imposed by supersymmetry, we will obtain the Ward identities
associated to two-point functions of $\tfrac{1}{2}$-BPS operators and write
their solution as a superconformal block expansion. Due to a surprising
connection between spacetime and R-symmetry conformal blocks, our results not
only apply to $4d$ $\mathcal{N}=4$ superconformal theories with a boundary, but
also to three more systems that have the same symmetry algebra: $4d$
$\mathcal{N}=4$ superconformal theories with a line defect, $3d$
$\mathcal{N}=4$ superconformal theories with no defect, and $OSP(4^*|4)$
superconformal quantum mechanics. The superconformal algebra implies that all
these systems possess a closed subsector of operators in which the bootstrap
equations become polynomial constraints on the CFT data. We derive these
truncated equations and initiate the study of their solutions.Comment: 44 pages, 2 figures, v3: typos fixed, to appear in JHE
Bulk viscous corrections to screening and damping in QCD at high
  temperatures

Non-equilibrium corrections to the distribution functions of quarks and
gluons in a hot and dense QCD medium modify the "hard thermal loops" (HTL). The
HTLs determine the retarded, advanced, and symmetric (time-ordered) propagators
for gluons with soft momenta as well as the Debye screening and Landau damping
mass scales. We compute such corrections to a thermal as well as to a
non-thermal fixed point.The screening and damping mass scales are sensitive to
the bulk pressure and hence to (pseudo-) critical dynamical scaling of the bulk
viscosity in the vicinity of a second-order critical point. This could be
reflected in the properties of quarkonium bound states in the deconfined phase
and in the dynamics of soft gluon fields.Comment: 19 pages. no figure, added corrections of quadratic order in the bulk
  pressure to the symmetric gluon self energy, to appear in JHE
Exactly marginal deformations from exceptional generalised geometry

We apply exceptional generalised geometry to the study of exactly marginal
deformations of $\mathcal{N}=1$ SCFTs that are dual to generic AdS$_5$ flux
backgrounds in type IIB or eleven-dimensional supergravity. In the gauge
theory, marginal deformations are parametrised by the space of chiral primary
operators of conformal dimension three, while exactly marginal deformations
correspond to quotienting this space by the complexified global symmetry group.
We show how the supergravity analysis gives a geometric interpretation of the
gauge theory results. The marginal deformations arise from deformations of
generalised structures that solve moment maps for the generalised
diffeomorphism group and have the correct charge under the generalised Reeb
vector, generating the R-symmetry. If this is the only symmetry of the
background, all marginal deformations are exactly marginal. If the background
possesses extra isometries, there are obstructions that come from fixed points
of the moment maps. The exactly marginal deformations are then given by a
further quotient by these extra isometries.
  Our analysis holds for any $\mathcal{N}=2$ AdS$_5$ flux background. Focussing
on the particular case of type IIB Sasaki-Einstein backgrounds we recover the
result that marginal deformations correspond to perturbing the solution by
three-form flux at first order. In various explicit examples, we show that our
expression for the three-form flux matches those in the literature and the
obstruction conditions match the one-loop beta functions of the dual SCFT.Comment: 52 page
A closer look at the $R_D$ and $R_{D^*}$ anomalies

The measurement of $R_D$ ($R_{D^*}$), the ratio of the branching fraction of
$\overline{B} \to D \tau \bar{\nu}_\tau (\overline{B} \to D^* \tau
\bar{\nu}_\tau)$ to that of $\overline{B} \to D l \bar{\nu}_l (\overline{B} \to
D^* l \bar{\nu}_l)$, shows $1.9 \sigma$ $(3.3 \sigma)$ deviation from its
Standard Model (SM) prediction. The combined deviation is at the level of $4
\sigma$ according to the Heavy Flavour Averaging Group (HFAG). In this paper,
we perform an effective field theory analysis (at the dimension-6 level) of
these potential New Physics (NP) signals assuming $\rm SU(3)_{C} \times
SU(2)_{L} \times U(1)_{Y}$ gauge invariance. We first show that, in general,
$R_D$ and $R_{D^*}$ are theoretically independent observables and hence, their
theoretical predictions are not correlated. We identify the operators that can
explain the experimental measurements of $R_D$ and $R_{D^*}$ individually and
also together. Motivated by the recent measurement of the $\tau$ polarisation
in $\overline{B} \to D^* \tau \bar{\nu}_\tau$ decay, $P_\tau (D^*)$ by the
Belle collaboration, we study the impact of a more precise measurement of
$P_\tau (D^*)$ (and a measurement of $P_\tau (D)$) on the various possible NP
explanations. Furthermore, we show that the measurement of $R_{D^*}$ in bins of
$q^2$, the square of the invariant mass of the lepton-neutrino system, along
with the information on $\tau$ polarisation and the forward-backward asymmetry
of the $\tau$ lepton, can completely distinguish the various operator
structures. We also provide the full expressions of the double differential
decay widths for the individual $\tau$ helicities in the presence of all the 10
dimension-6 operators that can contribute to these decays.Comment: Mistakes in section 8.1 corrected (not updated in the journal
  version
Partially Massless Higher-Spin Theory II: One-Loop Effective Actions

We continue our study of a generalization of the D-dimensional linearized
Vasiliev higher-spin equations to include a tower of partially massless (PM)
fields. We compute one-loop effective actions by evaluating zeta functions for
both the "minimal" and "non-minimal" parity-even versions of the theory.
Specifically, we compute the log-divergent part of the effective action in
odd-dimensional Euclidean AdS spaces for D=7 through 19 (dual to the a-type
conformal anomaly of the dual boundary theory), and the finite part of the
effective action in even-dimensional Euclidean AdS spaces for D=4 through 8
(dual to the free energy on a sphere of the dual boundary theory). We pay
special attention to the case D=4, where module mixings occur in the dual field
theory and subtlety arises in the one-loop computation. The results provide
evidence that the theory is UV complete and one-loop exact, and we conjecture
and provide evidence for a map between the inverse Newton's constant of the
partially massless higher-spin theory and the number of colors in the dual CFT.Comment: 36 pages. v2 clarifications, corrections and refs, version appearing
  in JHE
Bolting Multicenter Solutions

We introduce a solvable system of equations that describes non-extremal
multicenter solutions to six-dimensional ungauged supergravity coupled to
tensor multiplets. The system involves a set of functions on a
three-dimensional base metric. We obtain a family of non-extremal axisymmetric
solutions that generalize the known multicenter extremal solutions, using a
particular base metric that introduces a bolt. We analyze the conditions for
regularity, and in doing so we show that this family does not include solutions
that contain an extremal black hole and a smooth bolt. We determine the
constraints that are necessary to obtain smooth horizonless solutions involving
a bolt and an arbitrary number of Gibbons-Hawking centers.Comment: 32 page
One-loop divergences in 6D, N=(1,0) SYM theory

We consider, in the harmonic superspace approach, the six-dimensional N=(1,0)
supersymmetric Yang-Mills gauge multiplet minimally coupled to a hypermultiplet
in an arbitrary representation of the gauge group. Using the superfield
proper-time and background-field techniques, we compute the divergent part of
the one-loop effective action depending on both the gauge multiplet and the
hypermultiplet. We demonstrate that in the particular case of N=(1,1) SYM
theory, which corresponds to the hypermultiplet in the adjoint representation,
all one-loop divergencies vanish, so that N=(1,1) SYM theory is one-loop finite
{\it off shell}.Comment: 1 + 16 pages, published versio
Lattice operators for scattering of particles with spin

We construct operators for simulating the scattering of two hadrons with spin
on the lattice. Three methods are shown to give the consistent operators for
PN, PV, VN and NN scattering, where P, V and N denote pseudoscalar, vector and
nucleon. Explicit expressions for operators are given for all irreducible
representations at lowest two relative momenta. Each hadron has a good helicity
in the first method. The hadrons are in a certain partial wave L with total
spin S in the second method. These enable the physics interpretations of the
operators obtained from the general projection method. The correct
transformation properties of the operators in all three methods are proven. The
total momentum of two hadrons is restricted to zero since parity is a good
quantum number in this case.Comment: 29 pages, updated to match the version published by JHEP. The
  relation between partial-wave and helicity operators is now provided (Eq.
  4.13) and proved (Appendix D). Discussions on the applicability of the
  constructed operators and higher partial-waves have been extende
Hexagonalization of Correlation Functions

We propose a nonperturbative framework to study general correlation functions
of single-trace operators in $\mathcal{N}=4$ supersymmetric Yang-Mills theory
at large $N$. The basic strategy is to decompose them into fundamental building
blocks called the hexagon form factors, which were introduced earlier to study
structure constants using integrability. The decomposition is akin to a
triangulation of a Riemann surface, and we thus call it hexagonalization. We
propose a set of rules to glue the hexagons together based on symmetry, which
naturally incorporate the dependence on the conformal and the R-symmetry cross
ratios. Our method is conceptually different from the conventional operator
product expansion and automatically takes into account multi-trace operators
exchanged in OPE channels. To illustrate the idea in simple set-ups, we compute
four-point functions of BPS operators of arbitrary lengths and correlation
functions of one Konishi operator and three short BPS operators, all at one
loop. In all cases, the results are in perfect agreement with the perturbative
data. We also suggest that our method can be a useful tool to study conformal
integrals, and show it explicitly for the case of ladder integrals.Comment: 46 pages, v2: typos corrected, v3: a version to be publishe
Explicit reconstruction of the entanglement wedge

The problem of how the boundary encodes the bulk in AdS/CFT is still a
subject of study today. One of the major issues that needs more elucidation is
the problem of subregion duality; what information of the bulk a given boundary
subregion encodes. Although the proof given by Dong, Harlow, and Wall states
that the entanglement wedge of the bulk should be encoded in boundary
subregions, no explicit procedure for reconstructing the entanglement wedge was
given so far. In this paper, mode sum approach to obtaining smearing functions
for a single bulk scalar is generalised to include bulk reconstruction in the
entanglement wedge of boundary subregions. It is generally expectated that
solutions to the wave equation on a complicated coordinate patch are needed,
but this hard problem has been transferred to a less hard but tractable problem
of matrix inversion.Comment: version accepted by JHEP; added references and discussions on
  covarianc
Massive scalar field evolution in de Sitter

The behaviour of a massive, non-interacting and non-minimally coupled
quantised scalar field in an expanding de Sitter background is investigated by
solving the field evolution for an arbitrary initial state. In this approach
there is no need to choose a vacuum in order to provide a definition for
particle states. We conclude that the expanding de Sitter space is a stable
equilibrium configuration under small perturbations of the initial conditions.
Depending on the initial state, the energy density can approach its asymptotic
value from above or below, the latter of which implies a violation of the weak
energy condition. The backreaction of the quantum corrections can therefore
lead to a phase of super-acceleration also in the non-interacting massive case.Comment: 22 pages, 5 figures. v2: References added. v3: Expanded text, added
  references. Version accepted by JHE
Residual $Z_2$ symmetries and leptonic mixing patterns from finite
  discrete subgroups of $U(3)$

We study embedding of non-commuting $Z_2$ and $Z_m$, $m\geq 3$ symmetries in
discrete subgroups (DSG) of $U(3)$ and analytically work out the mixing
patterns implied by the assumption that $Z_2$ and $Z_m$ describe the residual
symmetries of the neutrino and the charged lepton mass matrices respectively.
Both $Z_2$ and $Z_m$ are assumed to be subgroups of a larger discrete symmetry
group $G_f$ possessing three dimensional faithful irreducible representation.
The residual symmetries predict the magnitude of a column of the leptonic
mixing matrix $U_{\rm PMNS}$ which are studied here assuming $G_f$ as the DSG
of $SU(3)$ designated as type C and D and large number of DSG of $U(3)$ which
are not in $SU(3)$. These include the known group series $\Sigma(3n^3)$,
$T_n(m)$, $\Delta(3n^2,m)$, $\Delta(6n^2,m)$ and $\Delta'(6n^2,j,k)$. It is
shown that the predictions for a column of $|U_{\rm PMNS}|$ in these group
series and the C and D types of groups are all contained in the predictions of
the $\Delta(6N^2)$ groups for some integer $N$. The $\Delta(6N^2)$ groups
therefore represent a sufficient set of $G_f$ to obtain predictions of the
residual symmetries $Z_2$ and $Z_m$.Comment: 27 pages, 1 figure, published versio
Gauge Mediation at LHC: status and prospects

We show that the predictivity of general gauge mediation (GGM) with TeV-scale
stops is greatly increased once the Higgs mass constraint is imposed. The most
notable results are a strong lower bound on the mass of the gluino and
right-handed squarks, and an upper bound on the Higgsino mass. If the
mu-parameter is positive, the wino mass is also bounded from above. These
constraints relax significantly for high messenger scales and as such
long-lived NLSPs are favored in GGM. We identify a small set of most promising
topologies for the neutralino/sneutrino NLSP scenarios and estimate the impact
of the current bounds and the sensitivity of the high luminosity LHC. The stau,
stop and sbottom NLSP scenarios can be robustly excluded at the high luminosity
LHC.Comment: Published version. 42 pages, 20 figures, LEP bounds revised and
  appendix added with a discussion of compressed spectr
Interacting fermions in rotation: chiral symmetry restoration, moment of
  inertia and thermodynamics

We study rotating fermionic matter at finite temperature in the framework of
the Nambu-Jona-Lasinio model. In order to respect causality the rigidly
rotating system must be bound by a cylindrical boundary with appropriate
boundary conditions that confine the fermions inside the cylinder. We show the
finite geometry with the MIT boundary conditions affects strongly the phase
structure of the model leading to three distinct regions characterized by
explicitly broken (gapped), partially restored (nearly gapless) and
spontaneously broken (gapped) phases at, respectively, small, moderate and
large radius of the cylinder. The presence of the boundary leads to specific
steplike irregularities of the chiral condensate as functions of coupling
constant, temperature and angular frequency. These steplike features have the
same nature as the Shubnikov-de Haas oscillations with the crucial difference
that they occur in the absence of both external magnetic field and Fermi
surface. At finite temperature the rotation leads to restoration of
spontaneously broken chiral symmetry while the vacuum at zero temperature is
insensitive to rotation ("cold vacuum cannot rotate"). As the temperature
increases the critical angular frequency decreases and the transition becomes
softer. A phase diagram in angular frequency-temperature plane is presented. We
also show that at fixed temperature the fermion matter in the chirally restored
(gapless) phase has a higher moment of inertia compared to the one in the
chirally broken (gapped) phase.Comment: 30 pages, 14 figures; v2: misprints correcte
Critical behavior of non-hydrodynamic quasinormal modes in a strongly
  coupled plasma

We study the behavior of quasinormal modes in a top-down holographic dual
corresponding to a strongly coupled $\mathcal{N} = 4$ super Yang-Mills plasma
charged under a $U(1)$ subgroup of the global $SU(4)$ R-symmetry. In
particular, we analyze the spectra of quasinormal modes in the external scalar
and vector diffusion channels near the critical point and obtain the behavior
of the characteristic equilibration times of the plasma as the system evolves
towards the critical point of its phase diagram. Except close to the critical
point, we observe that by increasing the chemical potential one generally
increases the damping rate of the quasinormal modes, which leads to a reduction
of the characteristic equilibration times in the dual strongly coupled plasma.
However, as one approaches the critical point the typical equilibration time
(as estimated from the lowest non-hydrodynamic quasinormal mode frequency)
increases, although remaining finite, while its derivative with respect to the
chemical potential diverges with exponent -1/2. We also find a purely imaginary
non-hydrodynamical mode in the vector diffusion channel at nonzero chemical
potential which dictates the equilibration time in this channel near the
critical point.Comment: 31 pages, 15 figures, version accepted for publication in JHE
Higher Dimensional Generalizations of the SYK Model

We discuss a 1+1 dimensional generalization of the Sachdev-Ye-Kitaev model.
The model contains $N$ Majorana fermions at each lattice site with a
nearest-neighbour hopping term. The SYK random interaction is restricted to low
momentum fermions of definite chirality within each lattice site. This gives
rise to an ordinary 1+1 field theory above some energy scale and a low energy
SYK-like behavior. We exhibit a class of low-pass filters which give rise to a
rich variety of hyperscaling behaviour in the IR. We also discuss another set
of generalizations which describes probing an SYK system with an external
fermion, together with the new scaling behavior they exhibit in the IR.Comment: 23 pages, 3 figures. Minor change
Baryon Superfluids in AdS/CFT with Flavor

Baryonic matter is notoriously difficult to deal with in the large-N limit,
as baryons become operators of very large dimension with N fields in the
fundamental representation. This issue is also present in gauge/gravity duals
as baryons are described by very heavy localized objects. There are however
alternative large-N extrapolations of QCD where small baryonic operators exist
and can be treated on an equal footing to mesons. We explore the possibility of
turning on a finite density of "light" baryons in a theory with a hadronic mass
gap using a gauge/gravity construction based on the D3/D7 intersection. We find
a novel phase with spontaneous breaking of baryon symmetry at zero temperature.Comment: 30 pages, 7 figure