pinecone/core-2020-05-10-deduplication huggingface dataset:
Universality in string interactions

In this letter, we provide evidence for universality in the low-energy
expansion of tree-level string interactions. More precisely, in the
alpha'-expansion of tree-level scattering amplitudes, we conjecture that the
leading transcendental coefficient at each order in alpha' is universal for all
perturbative string theories. We have checked this universality up to seven
points and trace its origin to the ability to restructure the disk integrals of
open bosonic string into those of the superstring. The accompanying kinematic
functions have the same low-energy limit and do not introduce any
transcendental numbers in their alpha'-corrections. Universality in the
closed-string sector then follows from the KLT-relations.Comment: 5 pages, Mathematica notebook on the five-point open-string amplitude
  included in submissio
Integrating out heavy particles with functional methods: a simplified
  framework

We present a systematic procedure to obtain the one-loop low-energy effective
Lagrangian resulting from integrating out the heavy fields of a given
ultraviolet theory. We show that the matching coefficients are determined
entirely by the hard region of the functional determinant involving the heavy
fields. This represents an important simplification with respect the
conventional matching approach, where the full and effective theory
contributions have to be computed separately and a cancellation of the infrared
divergent parts has to take place. We illustrate the method with a descriptive
toy model and with an extension of the Standard Model with a heavy real scalar
triplet. A comparison with other schemes that have been put forward recently is
also provided.Comment: 24 pages. Uses feynMF packag
Incorporating doubly resonant $W^\pm$ data in a global fit of SMEFT
  parameters to lift flat directions

We calculate the double pole contribution to two to four fermion scattering
through $W^{\pm}$ currents at tree level in the Standard Model Effective Field
Theory (SMEFT). We assume all fermions to be massless, $\rm U(3)^5$ flavour and
$\rm CP$ symmetry. Using this result, we update the global constraint picture
on SMEFT parameters including LEPII data on these charged current processes,
and also include modifications to our fit procedure motivated by a companion
paper focused on $W^{\pm}$ mass extractions. The fit reported is now to 177
observables and emphasises the need for a consistent inclusion of theoretical
errors, and a consistent treatment of observables. Including charged current
data lifts the two-fold degeneracy previously encountered in LEP (and lower
energy) data, and allows us to set simultaneous constraints on 20 of 53 Wilson
coefficients in the SMEFT, consistent with our assumptions. This allows the
model independent inclusion of LEP data in SMEFT studies at LHC, which are
projected into the SMEFT in a consistent fashion. We show how stronger
constraints can be obtained by using some combinations of Wilson coefficients,
when making assumptions on the UV completion of the Standard Model, or in an
inconsistent analysis. We explain why strong bounds at the per-mille or
sub-per-mille level on some combinations of Wilson coefficients in the
Effective Lagrangian can be artificially enhanced in fits of this form in
detail. This explains some of the different claims present in the literature.Comment: 27 pages + appendix, 9 fig, Acknowledgement updated with grant
  number
The Excitation of the Global Symmetry-Breaking Vacuum in Composite Higgs
  Models

We consider scenarios of Higgs compositeness where the Higgs doublet arises
as a pseudo-Nambu Goldstone boson. Our focus is the physical scalar ("radial")
excitation associated with the global symmetry breaking vacuum, which we call
the "global Higgs". For the minimal case of a $SO(5)/SO(4)$ coset, the
couplings of the global Higgs to Standard Model (SM) particles are fully
determined by group theoretical factors and two decay constants. The global
Higgs also couples to the composite resonances of the theory, inducing an
interaction with the SM gauge bosons at one-loop. We thoroughly analyze
representative fermionic sectors, considering a global Higgs both in the $\bf
5$ and $\bf 14$ representations of $SO(5)$ and taking into account the
renormalization group evolution of couplings in the composite sector. We derive
the one-loop effective couplings and all decays of the global Higgs, showing
that its decay width over mass can range from $ O (10^{-3})$ to $ O(1)$.
Because of the multiplicity of the resonances, the coupling of the global Higgs
to gluons is sizeable, potentially opening a new window into composite models
at the LHC.Comment: 27 pages, 2 figures. v3: References and comments added. Matches JHEP
  versio
Factorization and dispersion relations for radiative leptonic $B$ decay

Applying the dispersion approach we compute perturbative QCD corrections to
the power suppressed soft contribution of $B \to \gamma \ell \nu$ at leading
twist. QCD factorization for the $B \to \gamma^{\ast}$ form factors is
demonstrated explicitly for the hard-collinear transverse polarized photon at
one loop, with the aid of the method of regions. While the one-loop hard
function is identical to the matching coefficient of the QCD weak current $\bar
u \, \gamma_{\mu \perp} \, (1- \gamma_5) \, b$ in soft-collinear effective
theory, the jet function from integrating out the hard-collinear fluctuations
differs from the corresponding one entering the factorization formula of $B \to
\gamma \ell \nu$. Furthermore, we evaluate the sub-leading power contribution
to the $B \to \gamma$ form factors from the three-particle $B$-meson
distribution amplitudes (DAs) at tree level. The soft contribution to the $B
\to \gamma$ form factors from the three-particle $B$-meson DAs is shown to be
of the same power compared with the corresponding hard correction, in contrast
to the two-particle counterparts. Numerically the next-to-leading-order QCD
correction to the soft two-particle contribution in $B \to \gamma$ form factors
will induce an approximately $\left (10 \sim 20 \right) \%$ shift to the
tree-level contribution at $\lambda_B(\mu_0)=354 \, {\rm MeV}$. Albeit of power
suppression parametrically, the soft two-particle correction can decrease the
leading power predictions for the $B \to \gamma$ form factors by an amount of
$\left (10 \sim 30 \right) \%$ with the same value of $\lambda_B(\mu_0)$.
Employing the phenomenological model of the three-particle $B$-meson DAs
inspired by a QCD sum rule analysis, the three-particle contribution to the $B
\to \gamma$ form factors is predicted to be of ${\cal O} (1 \%)$, at leading
order in $\alpha_s$, with the default theory inputs.Comment: 32 pages, 9 figure
Effective Field Theory with Two Higgs Doublets

In this article we extend the effective field theory framework describing new
physics effects to the case where the underlying low-energy theory is a
Two-Higgs-Doublet model. We derive a complete set of independent operators up
to dimension six assuming a $Z_2$-invariant CP-conserving Higgs potential. The
effects on Higgs and gauge boson masses, mixing angles in the Higgs sector as
well as couplings to fermions and gauge bosons are computed. At variance with
the case of a single Higgs doublet, we find that pair production of SM-like
Higgses, arising through dimension-six operators, is not fixed by
fermion-fermion-Higgs couplings and can therefore be sizable.Comment: 19 pages, 8 table
Complexity Growth for AdS Black Holes

Recently a Complexity-Action (CA) duality conjecture has been proposed, which
relates the quantum complexity of a holographic boundary state to the action of
a Wheeler-DeWitt (WDW) patch in the anti-de Sitter (AdS) bulk. In this paper we
further investigate the duality conjecture for stationary AdS black holes and
derive some exact results for the growth rate of action within the
Wheeler-DeWitt (WDW) patch at late time approximation, which is supposed to be
dual to the growth rate of quantum complexity of holographic state. Based on
the results from the general $D$-dimensional Reissner-Nordstr\"{o}m (RN)-AdS
black hole, rotating/charged Ba\~{n}ados-Teitelboim-Zanelli (BTZ) black hole,
Kerr-AdS black hole and charged Gauss-Bonnet-AdS black hole, we present a
universal formula for the action growth expressed in terms of some
thermodynamical quantities associated with the outer and inner horizons of the
AdS black holes. And we leave the conjecture unchanged that the stationary AdS
black hole in Einstein gravity is the fastest computer in nature.Comment: v1, 10 pages, 2 figures, two columns; v2, 20 pages, 2 figures, JHEP
  style, references added; v3, 23 pages, 2 figures, discussions extended and
  references added, to be published in JHEP with title "Action Growth for AdS
  Black Holes
A scenario of heavy but visible baryonic dark matter

We consider a model in which dark matter is a composite baryon of a dark
sector governed by $SU(3)$ gauge theory, with vector-like quarks also charged
under $U(1)_Y$. The model provides simple answer to the dark matter stability
problem: it is a result of the accidental dark baryon number conservation. And
with an analogy to QCD, all physical quantities of the dark matter can be
calculated by rescaling the QCD experimental results. According to the thermal
freeze-out mechanism the mass of the dark matter is predicted to be
$\mathcal{O}(100)$~TeV in order to achieve a correct relic abundance. Such
heavy dark matter is in general hard for detection due to small dark matter
number density in the universe. However, dark baryon number in our model is not
necessarily strictly preserved thanks to operators suppressed by the Planck
scale, and such decay operator results in a decay lifetime marginal to the
current detection bound. We show our model with $\mathcal{O}(10^{27})~s$ dark
matter decay life time can explain the AMS-02 anti-proton data, if it is
experimentally interpreted as an access, although some theoretical uncertainty
may weaken its significance. We also investigate other phenomena of this model
such as the extragalactic gamma ray and neutrino signatures.Comment: 14 pages, 43 figures, published in JHE
Horizon supertranslation and degenerate black hole solutions

In this note we first review the degenerate vacua arising from the BMS
symmetries. According to the discussion in [1] one can define BMS-analogous
supertranslation and superrotation for spacetime with black hole in Gaussian
null coordinates. In the leading and subleading orders of near horizon
approximation, the infinitely degenerate black hole solutions are derived by
considering Einstein equations with or without cosmological constant, and they
are related to each other by the diffeomorphism generated by horizon
supertranslation. Higher order results and degenerate Rindler horizon solutions
also are given in appendices.Comment: 21 pages,no figures, references added, match the version published in
  JHE
Emergent Horizons and Causal Structures in Holography

The open string metric arises kinematically in studying fluctuations of open
string degrees of freedom on a D-brane. An observer, living on a probe D-brane,
can send signals through the spacetime by using such fluctuations on the probe,
that propagate in accordance with a metric which is conformal to the open
string metric. Event horizons can emerge in the open string metric when one
considers a D-brane with an electric field on its worldvolume. Here, we
emphasize the role of and investigate, in details, the causal structure of the
resulting open string event horizon and demonstrate, among other things, its
close similarities to an usual black hole event horizon in asymptotically
AdS-spaces. To that end, we analyze relevant geodesics, Penrose diagrams and
various causal holographic observables for a given open string metric. For
analytical control, most of our calculations are performed in an asymptotically
AdS$_3$-background, however, we argue that the physics is qualitatively the
same in higher dimensions. We also discuss how this open string metric arises
from an underlying D-brane configuration in string theory.Comment: 42 pages, multiple figure
Viability of exact tri-bimaximal, golden-ratio and bimaximal mixing
  patterns and renormalization-group running effects

In light of the latest neutrino oscillation data, we examine whether the
leptonic flavor mixing matrix can take on an exact form of tri-bimaximal (TBM),
golden-ratio (GR) or bimaximal (BM) mixing pattern at a superhigh-energy scale,
where such a mixing pattern could be realized by a flavor symmetry, and become
compatible with experimental data at the low-energy scale. Within the framework
of the Minimal Supersymmetric Standard Model (MSSM), the only hope for
realizing such a possibility is to count on the corrections from the
renomalization-group (RG) running. In this work we focus on these radiative
corrections, and fully explore the allowed parameter space for each of these
mixing patterns. We find that when the upper bound on the sum of neutrino
masses $\Sigma^{}_\nu \equiv m^{}_1 + m^{}_2 + m^{}_3 < 0.23~\text{eV}$ at the
$95\%$ confidence level from Planck 2015 is taken into account, none of these
mixing patterns can be identified as the leptonic mixing matrix below the
seesaw threshold. If this cosmological upper bound on the sum of neutrino
masses were relaxed, the TBM and GR mixing patterns would still be compatible
with the latest neutrino oscillation data at the $3\sigma$ level, but not at
the $1\sigma$ level. Even in this case, no such a possibility exists for the BM
mixing.Comment: 22 pages, 5 figures; minor changes, references added, version to
  appear in JHE
E$_{8(8)}$ Exceptional Field Theory: Geometry, Fermions and
  Supersymmetry

We present the supersymmetric extension of the recently constructed
E$_{8(8)}$ exceptional field theory -- the manifestly U-duality covariant
formulation of the untruncated ten- and eleven-dimensional supergravities. This
theory is formulated on a (3+248) dimensional spacetime (modulo section
constraint) in which the extended coordinates transform in the adjoint
representation of E$_{8(8)}$. All bosonic fields are E$_{8(8)}$ tensors and
transform under internal generalized diffeomorphisms. The fermions are tensors
under the generalized Lorentz group SO(1,2)$\times$SO(16), where SO(16) is the
maximal compact subgroup of E$_{8(8)}$. Vanishing generalized torsion
determines the corresponding spin connections to the extent they are required
to formulate the field equations and supersymmetry transformation laws. We
determine the supersymmetry transformations for all bosonic and fermionic
fields such that they consistently close into generalized diffeomorphisms. In
particular, the covariantly constrained gauge vectors of E$_{8(8)}$ exceptional
field theory combine with the standard supergravity fields into a single
supermultiplet. We give the complete extended Lagrangian and show its
invariance under supersymmetry. Upon solution of the section constraint the
theory reduces to full D=11 or type IIB supergravity.Comment: 25 page
Relevant deformations and c-extremization

We consider RG flows obtained by a relevant deformation from unitary and
compact two-dimensional (0,2) SCFTs. We point out that an N=2 super-Kac-Moody
algebra present in the UV is preserved by the flow and does not mix with the
R-current. On the other hand, a direct sum of N=2 algebras in the UV theory
leads to a few complications in determining the IR R-symmetry; nevertheless, in
flows without accidental IR symmetries, we determine the IR R-symmetry and show
that it maximizes the IR central charge.Comment: 10 pages; v2 minor revisio
Direct Evaluation of $n$-point single-trace MHV amplitudes in 4d
  Einstein-Yang-Mills theory using the CHY Formalism

In this paper we extend our techniques, developed in a previous paper (Du,
etc, JHEP 05(2016)086) for direct evaluation of arbitrary $n$-point tree-level
MHV amplitudes in 4d Yang-Mills and gravity theory using the Cachazo-He-Yuan
(CHY) formalism, to the 4d Einstein-Yang-Mills (EYM) theory. Any single-trace
color-ordered $n$-point tree-level MHV amplitude in EYM theory, obtained by a
direct evaluation of the CHY formula, is of an elegant factorized form of a
Parke-Taylor factor and a Hodges determinant, much simpler and more compact
than the existing formulas in the literature. We prove that our new expression
is equivalent to the conjectured Selivanov-Bern-De Freitas-Wong (SBDW) formula,
with the help of a new theorem showing that the SBDW generating function has a
graph theory interpretation. Together with Ref. (Du, etc, JHEP 05(2016)086), we
provide strong analytic evidence for hidden simplicity in quantum field theory.Comment: 26 pages, 1 figure; v2: some typo corrected, more references added,
  published versio
Monte Carlo study of Lefschetz thimble structure in one-dimensional
  Thirring model at finite density

We consider the one-dimensional massive Thirring model formulated on the
lattice with staggered fermions and an auxiliary compact vector (link) field,
which is exactly solvable and shows a phase transition with increasing the
chemical potential of fermion number: the crossover at a finite temperature and
the first order transition at zero temperature. We complexify its
path-integration on Lefschetz thimbles and examine its phase transition by
hybrid Monte Carlo simulations on the single dominant thimble. We observe a
discrepancy between the numerical and exact results in the crossover region for
small inverse coupling $\beta$ and/or large lattice size $L$, while they are in
good agreement at the lower and higher density regions. We also observe that
the discrepancy persists in the continuum limit keeping the temperature finite
and it becomes more significant toward the low-temperature limit. This
numerical result is consistent with our analytical study of the model's thimble
structure. And these results imply that the contributions of subdominant
thimbles should be summed up in order to reproduce the first order transition
in the low-temperature limit.Comment: 15 pages, 10 figures. The revised version of the manuscript. v4:
  Corrected a simple bug in implementing the HMC algorithm and replaced
  fig.4-10. Our main conclusions remain unchanged. Erratum published in JHE
Double-soft behavior of the dilaton of spontaneously broken conformal
  invariance

The Ward identities involving the currents associated to the spontaneously
broken scale and special conformal transformations are derived and used to
determine, through linear order in the two soft-dilaton momenta, the
double-soft behavior of scattering amplitudes involving two soft dilatons and
any number of other particles. It turns out that the double-soft behavior is
equivalent to performing two single-soft limits one after the other. We confirm
the new double-soft theorem perturbatively at tree-level in a $D$-dimensional
conformal field theory model, as well as nonperturbatively by using the
"gravity dual'' of ${\cal{N}}=4$ super Yang-Mills on the Coulomb branch; i.e.
the Dirac-Born-Infeld action on AdS${}_5 \times S^5$.Comment: 48 pages, one appendi
Hidden Simplicity of the Gravity Action

We derive new representations of the Einstein-Hilbert action in which
graviton perturbation theory is immensely simplified. To accomplish this, we
recast the Einstein-Hilbert action as a theory of purely cubic interactions
among gravitons and a single auxiliary field. The corresponding equations of
motion are the Einstein field equations rewritten as two coupled first-order
differential equations. Since all Feynman diagrams are cubic, we are able to
derive new off-shell recursion relations for tree-level graviton scattering
amplitudes. With a judicious choice of gauge fixing, we then construct an
especially compact form for the Einstein-Hilbert action in which all graviton
interactions are simply proportional to the graviton kinetic term. Our results
apply to graviton perturbations about an arbitrary curved background spacetime.Comment: 20 pages, 1 figur
Holographic Butterfly Effect and Diffusion in Quantum Critical Region

We investigate the butterfly effect and charge diffusion near the quantum
phase transition in holographic approach. We argue that their criticality is
controlled by the holographic scaling geometry with deformations induced by a
relevant operator at finite temperature. Specifically, in the quantum critical
region controlled by a single fixed point, the butterfly velocity decreases
when deviating from the critical point. While, in the non-critical region, the
behavior of the butterfly velocity depends on the specific phase at low
temperature. Moreover, in the holographic Berezinskii-Kosterlitz-Thouless
transition, the universal behavior of the butterfly velocity is absent.
Finally, the tendency of our holographic results matches with the numerical
results of Bose-Hubbard model. A comparison between our result and that in the
$O(N)$ nonlinear sigma model is also given.Comment: 41 pages, 7 figures, minor revisions, refs adde
Anomalous transport and holographic momentum relaxation

The chiral magnetic and vortical effects denote the generation of
dissipationless currents due to magnetic fields or rotation. They can be
studied in holographic models with Chern-Simons couplings dual to anomalies in
field theory. We study a holographic model with translation symmetry breaking
based on linear massless scalar field backgrounds. We compute the electric DC
conductivity and find that it can vanish for certain values of the translation
symmetry breaking couplings. Then we compute the chiral magnetic and chiral
vortical conductivities. They are completely independent of the holographic
disorder couplings and take the usual values in terms of chemical potential and
temperature. To arrive at this result we suggest a new definition of
energy-momentum tensor in presence of the gravitational Chern-Simons coupling.Comment: 12 pages,v2: ref. adde
Multi-component Fermionic Dark Matter and IceCube PeV scale Neutrinos in
  Left-Right Model with Gauge Unification

We consider a simple extension of the minimal left-right symmetric model
(LRSM) in order to explain the PeV neutrino events seen at the IceCube
experiment from a heavy decaying dark matter. The dark matter sector is
composed of two fermions: one at PeV scale and the other at TeV scale such that
the heavier one can decay into the lighter one and two neutrinos. The gauge
annihilation cross sections of PeV dark matter are not large enough to generate
its relic abundance within the observed limit. We include a pair of real scalar
triplets $\Omega_{L,R}$ which can bring the thermally overproduced PeV dark
matter abundance into the observed range through late time decay and consequent
entropy release thereby providing a consistent way to obtain the correct relic
abundance without violating the unitarity bound on dark matter mass. Another
scalar field, a bitriplet under left-right gauge group is added to assist the
heavier dark matter decay. The presence of an approximate global $U(1)_X$
symmetry can naturally explain the origin of tiny couplings required for
long-lived nature of these decaying particles. We also show, how such an
extended LRSM can be incorporated within a non-supersymmetric $SO(10)$ model
where the gauge coupling unification at a very high scale naturally accommodate
a PeV scale intermediate symmetry, required to explain the PeV events at
IceCube.Comment: 33 pages, 9 figures, 4 tables; error in relic density calculation
  fixed and discussion expanded for better clarity; matches published versio