pinecone/core-2020-05-10-deduplication huggingface dataset:
Probing Scalar Effective Field Theories with the Soft Limits of
  Scattering Amplitudes

We investigate the soft behaviour of scalar effective field theories (EFTs)
when there is a number of distinct derivative power counting parameters,
$\rho_1< \rho_2<\ldots < \rho_Q$. We clarify the notion of an enhanced soft
limit and use these to extend the scope of on-shell recursion techniques for
scalar EFTs. As an example, we perform a detailed study of theories with two
power counting parameters, $\rho_1=1$ and $\rho_2=2$, that include the shift
symmetric generalised galileons. We demonstrate that the minimally enhanced
soft limit uniquely picks out the Dirac-Born-Infeld (DBI) symmetry, including
DBI galileons. For the exceptional soft limit we uniquely pick out the special
galileon within the class of theories under investigation. We study the DBI
galileon amplitudes more closely, verifying the validity of the recursion
techniques in generating the six point amplitude, and explicitly demonstrating
the invariance of all amplitudes under DBI galileon duality.Comment: 22 page
Hadronic uncertainties in $B\to K^*\mu^+\mu^-$: a state-of-the-art
  analysis

In the absence of direct evidence for New Physics at present LHC energies,
the focus is set on the anomalies and discrepancies recently observed in rare
$b \to s\ell\ell$ transitions which can be interpreted as indirect hints.
Global fits have shown that an economical New Physics solution can
simultaneously alleviate the tensions in the various channels and can lead to a
significant improvement in the description of the data. Alternative
explanations within the Standard Model for part of the observed anomalies have
been proposed in terms of (unexpectedly large) hadronic effects at low dilepton
invariant mass and attributing tensions in protected observables to statistical
fluctuations or experimental errors. We review the treatment of hadronic
uncertainties in this kinematic regime for one of the most important channels,
$B \to K^*\mu^+\mu^-$, in a pedagogical way. We provide detailed arguments
showing that factorisable power corrections cannot account for the observed
anomalies and that an explanation through long-distance charm contributions is
disfavoured. Some optimized observables at very low dilepton invariant mass are
shown to be protected against contributions from the semileptonic coefficient
$C_9$ (including any associated long-distance charm effects), enhancing their
sensitivity to New Physics contributions to other Wilson coefficients. Finally,
we discuss how the recent measurement of $Q_5$ by Belle (and in the future by
LHCb and Belle-II) may provide a robust cross-check of our arguments.Comment: 38 pages and 4 Figures. Updated version. Additional appendix with
  predictions for the RK* ratio. h00 set to 0 to avoid the unphysical pole in
  longitudinal amplitudes which was introduced in Refs. [21,22]. All
  conclusions of the paper remain unchange
On timelike supersymmetric solutions of gauged minimal 5-dimensional
  supergravity

We analyze the timelike supersymmetric solutions of minimal gauged
5-dimensional supergravity for the case in which the K\"ahler base manifold
admits a holomorphic isometry and depends on two real functions satisfying a
simple second-order differential equation. Using this general form of the base
space, the equations satisfied by the building blocks of the solutions become
of, at most, fourth degree and can be solved by simple polynomic ansatzs. In
this way we construct two 3-parameter families of solutions that contain almost
all the timelike supersymmetric solutions of this theory with one angular
momentum known so far and a few more: the (singular) supersymmetric
Reissner-Nordstr\"om-AdS solutions, the three exact supersymmetric solutions
describing the three near-horizon geometries found by Gutowski and Reall, three
1-parameter asymptotically-AdS$_{5}$ black-hole solutions with those three
near-horizon geometries (Gutowski and Reall's black hole being one of them),
three generalizations of the G\"odel universe and a few potentially homogenous
solutions. A key r\^ole in finding these solutions is played by our ability to
write AdS$_{5}$'s K\"ahler base space ($\overline{\mathbb{CP}}^{2}$ or
SU$(1,2)/$U$(2)$) is three different, yet simple, forms associated to three
different isometries. Furthermore, our ansatz for the K\"ahler metric also
allows us to study the dimensional compactification of the theory and its
solutions in a systematic way.Comment: 57 pages. References and comments adde
Wilson lines, Grassmannians and Gauge Invariant Off-shell Amplitudes in
  N=4 SYM

In this paper we consider tree-level gauge invariant off-shell amplitudes
(Wilson line form factors) in $\mathcal{N}=4$ SYM. For the off-shell amplitudes
with one leg off-shell we present a conjecture for their Grassmannian integral
representation in spinor helicity, twistor and momentum twistor
parameterizations. The presented conjecture is successfully checked against
BCFW results for MHV$_n$, NMHV$_4$ and NMHV$_5$ off-shell amplitudes. We have
also verified that our Grassmannian integral representation correctly
reproduces soft (on-shell) limit for the off-shell gluon momentum. It is shown
that the (deformed) off-shell amplitude expressions could be also obtained
using quantum inverse scattering method for auxiliary $gl(4|4)$ super spin
chain.Comment: 55 pages, 7 figures; v2: minor changes, typos corrected, references
  adde
Conformal higher spin scattering amplitudes from twistor space

We use the formulation of conformal higher spin (CHS) theories in twistor
space to study their tree-level scattering amplitudes, finding expressions for
all three-point anti-MHV amplitudes and all MHV amplitudes involving positive
helicity conformal gravity particles and two negative helicity higher spins.
This provides the on-shell analogue for the covariant coupling of CHS fields to
a conformal gravity background. We discuss the restriction of the theory to a
ghost-free unitary subsector, analogous to restricting conformal gravity to
general relativity with a cosmological constant. We study the flat-space limit
and show that the restricted amplitudes vanish, supporting the conjecture that
in the unitary sector the S-matrix of CHS theories is trivial. However, by
appropriately rescaling the amplitudes we find non-vanishing results which we
compare with chiral flat-space higher spin theories.Comment: 31 pages, no figures. v2: comments added, published versio
Deformations, Moduli Stabilisation and Gauge Couplings at One-Loop

We investigate deformations of $\mathbb{Z}_2$ orbifold singularities on the
toroidal orbifold $T^6/(\mathbb{Z}_2\times\mathbb{Z}_6)$ with discrete torsion
in the framework of Type IIA orientifold model building with intersecting
D6-branes wrapping special Lagrangian cycles. To this aim, we employ the
hypersurface formalism developed previously for the orbifold
$T^6/(\mathbb{Z}_2\times\mathbb{Z}_2)$ with discrete torsion and adapt it to
the $\mathbb{Z}_2\times\mathbb{Z}_6\times\Omega\mathcal{R}$ point group by
modding out the remaining $\mathbb{Z}_3$ subsymmetry and the orientifold
projection $\Omega\mathcal{R}$. We first study the local behaviour of the
$\mathbb{Z}_3\times\Omega\mathcal{R}$ invariant deformation orbits under
non-zero deformation and then develop methods to assess the deformation effects
on the fractional three-cycle volumes globally. We confirm that D6-branes
supporting USp(2N) or SO(2N) gauge groups do not constrain any deformation,
while deformation parameters associated to cycles wrapped by D6-branes with
U(N) gauge groups are constrained by D-term supersymmetry breaking. These
features are exposed in global prototype MSSM, Left-Right symmetric and
Pati-Salam models first constructed in arXiv:1509.00048 and arXiv:1409.1236,
for which we here count the number of stabilised moduli and study flat
directions changing the values of some gauge couplings. Finally, we confront
the behaviour of tree-level gauge couplings under non-vanishing deformations
along flat directions with the one-loop gauge threshold corrections at the
orbifold point and discuss phenomenological implications, in particular on
possible LARGE volume scenarios and the corresponding value of the string scale
$M_{\text{string}}$, for the same global D6-brane models.Comment: 1+84 pages, 16 figures, 32 table
Exploring viable vacua of the $Z_3$-symmetric NMSSM

We explore the vacua of the $Z_3$-symmetric Next-to-Minimal Supersymmetric
Standard Model (NMSSM) and their stability by going beyond the simplistic
paradigm that works with a tree-level neutral scalar potential and adheres to
some specific flat directions in the field space. Key effects are demonstrated
by first studying the profiles of this potential under various circumstances of
physical interest via a semi-analytical approach. The results thereof are
compared to the ones obtained from a dedicated package like \veva ~which
further incorporates the thermal effects to the potential. Regions of the
phenomenological NMSSM (pNMSSM) parameter space that render the desired
symmetry breaking (DSB) vacuum absolutely stable, long- or short-lived (in
relation to the age of the Universe) under quantum/thermal tunneling are
delineated. Regions that result in color and charge breaking (CCB) minima are
also presented. It is demonstrated that light singlet scalars along with a
light LSP (lightest supersymmetric particle) having an appreciable singlino
admixture are compatible with a viable DSB vacuum and are much relevant for the
collider experiments.Comment: 52 pages, 19 figures, 4 tables; matches with published versio
Equivalence of Two Contour Prescriptions in Superstring Perturbation
  Theory

Conventional superstring perturbation theory based on the world-sheet
approach gives divergent results for the S-matrix whenever the total center of
mass energy of the incoming particles exceeds the threshold of production of
any final state consistent with conservation laws. Two systematic approaches
have been suggested for dealing with this difficulty. The first one involves
deforming the integration cycles over the moduli space of punctured Riemann
surfaces into complexified moduli space. The second one treats the amplitude as
a sum of superstring field theory Feynman diagrams and deforms the integration
contours over loop energies of the Feynman diagram into the complex plane. In
this paper we establish the equivalence of the two prescriptions to all orders
in perturbation theory. Since the second approach is known to lead to unitary
amplitudes, this establishes the consistency of the first prescription with
unitarity.Comment: LaTeX, 12 page
Evolving Planck Mass in Classically Scale-Invariant Theories

We consider classically scale-invariant theories with non-minimally coupled
scalar fields, where the Planck mass and the hierarchy of physical scales are
dynamically generated. The classical theories possess a fixed point, where
scale invariance is spontaneously broken. In these theories, however, the
Planck mass becomes unstable in the presence of explicit sources of scale
invariance breaking, such as non-relativistic matter and cosmological constant
terms. We quantify the constraints on such classical models from Big Bang
Nucleosynthesis that lead to an upper bound on the non-minimal coupling and
require trans-Planckian field values. We show that quantum corrections to the
scalar potential can stabilise the fixed point close to the minimum of the
Coleman-Weinberg potential. The time-averaged motion of the evolving fixed
point is strongly suppressed, thus the limits on the evolving gravitational
constant from Big Bang Nucleosynthesis and other measurements do not presently
constrain this class of theories. Field oscillations around the fixed point, if
not damped, contribute to the dark matter density of the Universe.Comment: 28 pages, 2 figures, version published in JHE
Constraints on new physics from radiative $B$ decays

A new phase for the measurements of radiative decay modes in $b \to s$
transitions has started with new measurements of exclusive modes by LHCb and
with Belle-II showing distinctive promises in both inclusive and exclusive
channels. After critically reviewing the hadronic uncertainties in exclusive
radiative decays, we analyze the impact of recent measurements of the branching
ratio and mass-eigenstate rate asymmetry in $B_s\to\phi\gamma$ and of the
angular distribution of $B\to K^*e^+e^-$ at low $q^2$ on new physics in the
$b\to s\gamma$ transition.Comment: 22 pages, 3 figures. v3: Minor numerical updates, references added,
  one figure added. Conclusions unchange
T-duality orbifolds of heterotic Narain compactifications

To obtain a unified framework for symmetric and asymmetric heterotic orbifold
constructions we provide a systematic study of Narain compactifications
orbifolded by finite order T-duality subgroups. We review the generalized
vielbein that parametrizes the Narain moduli space (i.e. the metric, the
B-field and the Wilson lines) and introduce a convenient basis of generators of
the heterotic T-duality group. Using this we generalize the space group
description of orbifolds to Narain orbifolds. This yields a unified,
crystallographic description of the orbifold twists, shifts as well as Narain
moduli. In particular, we derive a character formula that counts the number of
unfixed Narain moduli after orbifolding. Moreover, we develop new machinery
that may ultimately open up the possibility for a full classification of Narain
orbifolds. This is done by generalizing the geometrical concepts of Q-, Z- and
affine classes from the theory of crystallography to the Narain case. Finally,
we give a variety of examples illustrating various aspects of Narain orbifolds,
including novel T-folds.Comment: 1+59 pages LaTeX, 1 figure. v2: references added, typos corrected;
  published versio
Confining gauge theories and holographic entanglement entropy with a
  magnetic field

We consider the soft wall model for a heuristic holographical modelling of a
confining gauge theory and discuss how the introduction of a (constant)
magnetic field influences the (de)confinement phase structure. We use the
entanglement entropy as a diagnostic tool in terms of the length of an
entangling strip geometry. Due to the anisotropy introduced by the magnetic
field, we find that the results depend on the orientation of the strip relative
to the field. This allows to identify a richer, anisotropic, interplay between
confinement and a magnetic field than possibly can be extracted from a more
standard order parameter as, for example, the Polyakov loop expectation value.Comment: 25 pages, 31 figure
Bootstrapping $\mathcal{N}=3$ superconformal theories

We initiate the bootstrap program for $\mathcal{N}=3$ superconformal field
theories (SCFTs) in four dimensions. The problem is considered from two fronts:
the protected subsector described by a $2d$ chiral algebra, and crossing
symmetry for half-BPS operators whose superconformal primaries parametrize the
Coulomb branch of $\mathcal{N}=3$ theories. With the goal of describing a
protected subsector of a family of $\mathcal{N}=3$ SCFTs, we propose a new $2d$
chiral algebra with super Virasoro symmetry that depends on an arbitrary
parameter, identified with the central charge of the theory. Turning to the
crossing equations, we work out the superconformal block expansion and apply
standard numerical bootstrap techniques in order to constrain the CFT data. We
obtain bounds valid for any theory but also, thanks to input from the chiral
algebra results, we are able to exclude solutions with $\mathcal{N}=4$
supersymmetry, allowing us to zoom in on a specific $\mathcal{N}=3$ SCFT.Comment: 54 pages (43 plus five appendices), 7 figures; v2: improvements for
  clarit
BCJ numerators from reduced Pfaffian

By expanding the reduced Pfaffian in the tree level Cachazo-He-Yuan (CHY)
integrands for Yang-Mills (YM) and nonlinear sigma model (NLSM), we can get the
Bern-Carrasco-Johansson (BCJ) numerators in Del Duca-Dixon-Maltoni (DDM) form
for arbitrary number of particles in any spacetime dimensions. In this work, we
give a set of very straightforward graphic rules based on spanning trees for a
direct evaluation of the BCJ numerators for YM and NLSM. Such rules can be
derived from the Laplace expansion of the corresponding reduced Pfaffian. For
YM, the each one of the $(n-2)!$ DDM form BCJ numerators contains exactly
$(n-1)!$ terms, corresponding to the increasing trees with respect to the color
order. For NLSM, the number of nonzero numerators is at most $(n-2)!-(n-3)!$,
less than those of several previous constructions.Comment: 29 pages, 3 captioned figure
Majorana Dark matter with B+L gauge symmetry

We present a new model that extends the Standard Model (SM) with the local
B+L symmetry, and point out that the lightest new fermion $\zeta$, introduced
to cancel anomalies and stabilized automatically by the B+L symmetry, can serve
as the cold dark matter candidate. We study constraints on the model from Higgs
measurements, electroweak precision measurements as well as the relic density
and direct detections of the dark matter. Numerical results reveal that the
pseudo-vector coupling of $\zeta$ with $Z$ and the Yukawa coupling with the SM
Higgs are highly constrained by the latest results of LUX, while there are
viable parameter space that could satisfy all the constraints and give testable
predictions.Comment: 17 pages, 4 figures, minor revision, more references adde
Holographic Photon Production in Heavy Ion Collisions

The thermal-photon emission from strongly coupled gauge theories at finite
temperature is calculated using holographic models for QCD in the Veneziano
limit (V-QCD). The emission rates are then embedded in hydrodynamic simulations
combined with prompt photons from hard scattering and the thermal photons from
hadron gas to analyze the spectra and anisotropic flow of direct photons at
RHIC and LHC. The results from different sources responsible for the thermal
photons in QGP including the weakly coupled QGP (wQGP) from perturbative
calculations, strongly coupled $\mathcal{N}=4$ super Yang-Mills (SYM) plasma
(as a benchmark for reference), and Gubser's phenomenological holographic model
are then compared. It is found that the direct-photon spectra are enhanced in
the strongly coupled scenario compared with the ones in the wQGP, especially at
high momenta. Moreover, both the elliptic flow and triangular flow of direct
photons are amplified at high momenta for V-QCD and the SYM plasma. The results
are further compared with experimental observations.Comment: 39 pages, 14 figures; spectra and flow updated with NLO pQCD rates;
  an appendix added, conclusions remained unchanged; typos corrected; journal
  versio
Symmetry restoration at high-temperature in two-color and two-flavor
  lattice gauge theories

We consider the $SU(2)$ gauge theory with $N_f=2$ flavors of Dirac
fundamental fermions. We study the high-temperature behavior of the spectra of
mesons, discretizing the theory on anisotropic lattices, and measuring the
two-point correlation functions in the temporal direction as well as screening
masses in various channels. We identify the (pseudo-)critical temperature as
the temperature at which the susceptibility associated with the Polyakov loop
has a maximum. At high temperature both the spin-1 and spin-0 sectors of the
light meson spectra exhibit enhanced symmetry properties, indicating the
restoration of both the global $SU(4)$ and the axial $U(1)_A$ symmetries of the
model.Comment: 38 pages, 14 figures, 6 tables, Version accepted for publicatio
Entanglement renormalization, quantum error correction, and bulk
  causality

Entanglement renormalization can be viewed as an encoding circuit for a
family of approximate quantum error correcting codes. The logical information
becomes progressively more well-protected against erasure errors at larger
length scales. In particular, an approximate variant of holographic quantum
error correcting code emerges at low energy for critical systems. This implies
that two operators that are largely separated in scales behave as if they are
spatially separated operators, in the sense that they obey a Lieb-Robinson type
locality bound under a time evolution generated bya local Hamiltonian.Comment: 10 pages, 5 figures. typos correcte
Electroweak Kaluza-Klein Dark Matter

In models with universal extra dimensions (UED), the lightest Kaluza-Klein
excitation of neutral electroweak gauge bosons is a stable, weakly interacting
massive particle and thus is a candidate for dark matter thanks to Kaluza-Klein
parity. We examine concrete model realizations of such dark matter in the
context of non-minimal UED extensions. The boundary localized kinetic terms for
the electroweak gauge bosons lead to a non-trivial mixing among the first
Kaluza-Klein excitations of the ${\rm SU}(2)_W$ and ${\rm U}(1)_Y$ gauge bosons
and the resultant low energy phenomenology is rich. We investigate implications
of various experiments including low energy electroweak precision measurements,
direct and indirect detection of dark matter particles and direct collider
searches at the LHC. Notably, we show that the electroweak Kaluza-Klein dark
matter can be as heavy as 2.4 TeV, which is significantly higher than $1.3$ TeV
as is indicated as an upper bound in the minimal UED model.Comment: 29 pages, 10 figures, 1 table; v2: Fig 10 added, remarks on the
  potential influence of Sommerfeld enhancement added, typos corrected,
  references added, version published in JHE
Loop effects of heavy new scalars and fermions in $b\to s\mu^+\mu^-$

Recent measurements of $b\to s\mu^+\mu^-$ processes at LHCb and BELLE have
revealed tensions at the $2-3\,\sigma$ level between the Standard Model (SM)
prediction and the experimental results in the channels $B\to K^*\mu^+\mu^-$
and $B_s\to\phi\mu^+\mu^-$, as well as in the lepton-flavor universality
violating observable $R_K={\rm Br}(B\to K\mu^+\mu^-)/{\rm Br}(B\to Ke^+e^-$).
Combined global fits to the available $b\to s\mu^+\mu^-$ data suggest that
these tensions might have their common origin in New Physics (NP) beyond the SM
because some NP scenarios turn out to be preferred over the SM by
$4-5\,\sigma$. The fact that all these anomalies are related to muons further
suggests a connection (and a common NP explanation) with the long-standing
anomaly in the anomalous magnetic moment of the muon, $a_\mu$. In this article,
we study the impact of a generic class of NP models featuring new heavy scalars
and fermions that couple to the SM fermions via Yukawa-like interactions. We
consider two different scenarios, introducing either one additional fermion and
two scalars or two additional fermions and one scalar, and examine all possible
representations of the new particles under the SM gauge group with dimension up
to the adjoint one. The models induce one-loop contributions to $b\to
s\mu^+\mu^-$ and $a_\mu$ which are capable of solving the respective anomalies
at the $2\sigma$ level, albeit a relatively large coupling of the new particles
to muons is required. In the case of $b\to s\mu^+\mu^-$, stringent constraints
from $B_s-\overline{B}_s$ mixing arise which can be relaxed if the new fermion
is a Majorana particle.Comment: 24 pages, 7 figures, discussion of D-meson mixing and Z --> mu^+ mu^-
  added, conclusions unchanged, journal versio