pinecone/core-2020-05-10-deduplication huggingface dataset:
String pair production in non homogeneous backgrounds

We consider string pair production in non homogeneous electric backgrounds.
We study several particular configurations which can be addressed with the
Euclidean world-sheet instanton technique, the analogue of the world-line
instanton for particles. In the first case the string is suspended between two
D-branes in flat space-time, in the second case the string lives in AdS and
terminates on one D-brane (this realizes the holographic Schwinger effect). In
some regions of parameter space the result is well approximated by the known
analytical formulas, either the particle pair production in non-homogeneous
background or the string pair production in homogeneous background. In other
cases we see effects which are intrinsically stringy and related to the
non-homogeneity of the background. The pair production is enhanced already for
particles in time dependent electric field backgrounds. The string nature
enhances this even further. For spacial varying electrical background fields
the string pair production is less suppressed than the rate of particle pair
production. We discuss in some detail how the critical field is affected by the
non-homogeneity, for both time and space dependent electric field backgrouds.
We also comment on what could be an interesting new prediction for the small
field limit. The third case we consider is pair production in holographic
confining backgrounds with homogeneous and non-homogeneous fields.Comment: 36 pages; v3: added comments on perturbative vs. non-perturbative
  behaviou
Four-jet production in single- and double-parton scattering within
  high-energy factorization

We perform a first study of 4-jet production in a complete high-energy
factorization (HEF) framework. We include and discuss contributions from both
single-parton scattering (SPS) and double-parton scattering (DPS). The
calculations are performed for kinematical situations relevant for two
experimental measurements (ATLAS and CMS) at the LHC. We compare our results to
those reported by the ATLAS and CMS collaborations for different sets of
kinematical cuts. The results of the HEF approach are compared with their
counterparts for collinear factorization. For symmetric cuts the DPS HEF result
is considerably smaller than the one obtained with collinear factorization. The
mechanism leading to this difference is of kinematical nature. We conclude that
an analysis of inclusive 4-jet production with asymmetric $p_T$-cuts below 50
GeV would be useful to enhance the DPS contribution relative to the SPS
contribution. In contrast to the collinear approach, the HEF approach nicely
describes the distribution of the $\Delta S$ variable, which involves all four
jets and their angular correlations.Comment: 18 pages, 14 figure
A note on entanglement entropy for topological interfaces in RCFTs

In this paper we calculate the entanglement entropy for topological
interfaces in rational conformal field theories for the case where the
interface lies at the boundary of the entangling interval and for the case
where it is located in the center of the entangling interval. We compare the
results to each other and also to the recently calculated left/right entropy of
a related BCFT. We also comment of the entanglement entropies for topological
interfaces for a free compactified boson and Liouville theory.Comment: 17 pages, pdflatex, 2 figures, v2: references added, typos corrected
  and figure 2 improved, v3: minor correctio
Radiative natural SUSY spectrum from deflected AMSB scenario with
  messenger-matter interactions

A radiative natural SUSY spectrum are proposed in the deflected anomaly
mediation scenario with general messenger-matter interactions. Due to the
contributions from the new interactions, positive slepton masses as well as a
large |A_t| term can naturally be obtained with either sign of deflection
parameter and few messenger species (thus avoid the possible Landau pole
problem). In this scenario, in contrast to the ordinary (radiative) natural
SUSY scenario with under-abundance of dark matter (DM), the DM can be the mixed
bino-higgsino and have the right relic density. The 125 GeV Higgs mass can also
be easily obtained in our scenario. The majority of low EW fine tuning points
can be covered by the XENON-1T direct detection experiments.Comment: Discussions added; 16 pages, 2 figure
Moduli spaces of AdS_5 vacua in N=2 supergravity

We determine the conditions for maximally supersymmetric AdS_5 vacua of
five-dimensional gauged N=2 supergravity coupled to vector-, tensor- and
hypermultiplets charged under an arbitrary gauge group. In particular, we show
that the unbroken gauge group of the AdS_5 vacua has to contain an
U(1)_R-factor. Moreover we prove that the scalar deformations which preserve
all supercharges form a Kahler submanifold of the ambient quaternionic Kahler
manifold spanned by the scalars in the hypermultiplets.Comment: 17 page
Conserved Currents of Double Field Theory

We find the conserved current associated to invariance under generalised
diffeomorphisms in double field theory. This can be used to define a
generalised Komar integral. We comment on its applications to solutions, in
particular to the fundamental string/pp-wave. We also discuss the current in
the context of Scherk-Schwarz compactifications. We calculate the current for
both the original double field theory action, corresponding to the NSNS sector
alone, and for the RR sector.Comment: 30 pages + appendix, v2: belated update to match published version
  (typos + refs fixed, some minor comments added
Instabilities of microstate geometries with antibranes

One can obtain very large classes of horizonless microstate geometries
corresponding to near-extremal black holes by placing probe supertubes whose
action has metastable minima inside certain supersymmetric bubbling solutions.
We show that these minima can lower their energy when the bubbles move in
certain directions in the moduli space, which implies that these near-extremal
microstates are in fact unstable once one considers the dynamics of all their
degrees of freedom. The decay of these solutions corresponds to Hawking
radiation, and we compare the emission rate and frequency to those of the
corresponding black hole. Our analysis supports the expectation that generic
non-extremal black holes microstate geometries should be unstable. It also
establishes the existence of a new type of instabilities for antibranes in
highly-warped regions with charge dissolved in fluxes.Comment: 24 pages, 4 figure
Less-simplified models of dark matter for direct detection and the LHC

We construct models of dark matter with suppressed spin-independent
scattering cross section utilizing the existing simplified model framework.
Even simple combinations of simplified models can exhibit interference effects
that cause the tree level contribution to the scattering cross section to
vanish, thus demonstrating that direct detection limits on simplified models
are not robust when embedded in a more complicated and realistic framework. In
general for fermionic WIMP masses >10 GeV direct detection limits on the
spin-independent scattering cross section are much stronger than those coming
from the LHC. However these model combinations, which we call less-simplified
models, represent situations where LHC searches become more competitive than
direct detection experiments even for moderate dark matter mass. We show that a
complementary use of several searches at the LHC can strongly constrain the
direct detection blind spots by setting limits on the coupling constants and
mediators' mass. We derive the strongest limits for combinations of vector +
scalar, vector + "squark", and "squark" + scalar mediator, and present the
corresponding projections for the LHC 14 TeV for a number of searches:
mono-jet, jets + missing energy, and searches for heavy vector resonances.Comment: 29 pages, 9 figures. Text matches published version. References adde
M2-brane surface operators and gauge theory dualities in Toda

We give a microscopic two dimensional ${\cal N}=(2,2)$ gauge theory
description of arbitrary M2-branes ending on $N_f$ M5-branes wrapping a
punctured Riemann surface. These realize surface operators in four dimensional
${\cal N}=2$ field theories. We show that the expectation value of these
surface operators on the sphere is captured by a Toda CFT correlation function
in the presence of an additional degenerate vertex operator labelled by a
representation ${\cal R}$ of $SU(N_f)$, which also labels M2-branes ending on
M5-branes. We prove that symmetries of Toda CFT correlators provide a geometric
realization of dualities between two dimensional gauge theories, including
${\cal N}=(2,2)$ analogues of Seiberg and Kutasov--Schwimmer dualities. As a
bonus, we find new explicit conformal blocks, braiding matrices, and fusion
rules in Toda CFT.Comment: 74 pages + appendices, LaTeX. v2: references adde
Reflections on Conformal Spectra

We use modular invariance and crossing symmetry of conformal field theory to
reveal approximate reflection symmetries in the spectral decompositions of the
partition function in two dimensions in the limit of large central charge and
of the four-point function in any dimension in the limit of large scaling
dimensions $\Delta_0$ of external operators. We use these symmetries to
motivate universal upper bounds on the spectrum and the operator product
expansion coefficients, which we then derive by independent techniques. Some of
the bounds for four-point functions are valid for finite $\Delta_0$ as well as
for large $\Delta_0$. We discuss a similar symmetry in a large spacetime
dimension limit. Finally, we comment on the analogue of the Cardy formula and
sparse light spectrum condition for the four-point function.Comment: 13 pages, 5 figure
Five-body leptonic decays of muon and tau leptons

We study the five-body decays $\mu^- \to e^- e^+ e^- \nu_{\mu} \bar{\nu}_{e}$
and $\tau^- \to \ell^- \ell'^+\ell'^-\nu_{\tau}\bar{\nu}_{\ell}$ for $\ell,
\ell'=e, \mu$ within the Standard Model (SM) and in a general effective field
theory description of the weak interactions at low energies. We compute the
branching ratios and compare our results with two previous, mutually
discrepant, SM calculations. By assuming a general structure for the weak
currents we derive the expressions for the energy and angular distributions of
the three charged leptons when the decaying lepton is polarized, which will be
useful in precise tests of the weak charged current at Belle II. In these
decays, leptonic $\mathbf{T}$-odd correlations in triple products of spin and
momenta --which may signal time reversal violation in the leptonic sector-- are
suppressed by the tiny neutrino masses. Therefore, a measurement of such
$\mathbf{T}$-violating observables would be associated to neutrinoless lepton
flavor violating (LFV) decays, where this effect is not extremely suppressed.
We also study the backgrounds that the SM five-lepton lepton decays constitute
to searches of LFV $L^- \to \ell^- \ell'^+\ell'^-$ decays. Searches at high
values of the invariant mass of the $\ell'^+\ell'^-$ pair look the most
convenient way to overcome the background.Comment: 40 pages, 6 figures, extended discussion of results in the case of
  the effective lagrangian approach; other minor corrections/modifications are
  adde
Constraints on Leptoquark Models from IceCube Data

Leptoquarks in the mass range of 500-1000 GeV can be resonantly produced in
significant numbers by PeV neutrino interacting with nuclei at IceCube. We
compute the event rates of leptoquark production and decay events and use the
3-year IceCube data for PeV energy events to find the allowed range of the
leptoquarks mass and coupling parameter space. We use a low-scale quark lepton
unification model based on the $SU(4)_C \otimes SU(2)_L\otimes U(1)_R$ gauge
group where leptoquark couplings which give rise to proton decay are forbidden
by the symmetry. We constrain the parameters of this model and point out
signals of leptoquarks in this model which may be seen in PeV energy IceCube
events in the future.Comment: 11 pages, 4 figures, 1 table; a few typos fixed; matches published
  versio
The $\Lambda_2$ limit of massive gravity

Lorentz-invariant massive gravity is usually associated with a strong
coupling scale $\Lambda_3$. By including non-trivial effects from the
Stueckelberg modes, we show that about these vacua, one can push the strong
coupling scale to higher values and evade the linear vDVZ-discontinuity. For
generic parameters of the theory and generic vacua for the Stueckelberg fields,
the $\Lambda_2$-decoupling limit of the theory is well-behaved and free of any
ghost or gradient-like instabilities. We also discuss the implications for
nonlinear sigma models with Lorentzian target spaces.Comment: 38 pages, 1 figure, JHEP version, minor change
Superspace Higher Derivative Terms in Two Dimensions

We study $(2,2)$ and $(4,4)$ supersymmetric theories with superspace higher
derivatives in two dimensions. A characteristic feature of these models is that
they have several different vacua, some of which break supersymmetry. Depending
on the vacuum, the equations of motion describe different propagating degrees
of freedom. Various examples are presented which illustrate their generic
properties. As a by-product we see that these new vacua give a dynamical way of
generating non-linear realizations. In particular, our 2D $(4,4)$ example is
the dimensional reduction of a 4D $N=2$ model, and gives a new way for the
spontaneous breaking of extended supersymmetry.Comment: 23 pages, v3: comments added, published versio
Towards 4-point correlation functions of any 1/2-BPS operators from
  supergravity

The quartic effective action for Kaluza-Klein modes that arises upon
compactification of type IIB supergravity on the five-sphere S^5 is a starting
point for computing the four-point correlation functions of arbitrary weight
1/2-BPS operators in N=4 super Yang-Mills theory in the supergravity
approximation. The apparent structure of this action is rather involved, in
particular it contains quartic terms with four derivatives which cannot be
removed by field redefinitions. By exhibiting intricate identities between
certain integrals involving spherical harmonics of S^5 we show that the net
contribution of these four-derivative terms to the effective action vanishes.
Our result is in agreement with and provides further support to the recent
conjecture on the Mellin space representation of the four-point correlation
function of any 1/2-BPS operators in the supergravity approximation.Comment: 12 page
Transforming differential equations of multi-loop Feynman integrals into
  canonical form

The method of differential equations has been proven to be a powerful tool
for the computation of multi-loop Feynman integrals appearing in quantum field
theory. It has been observed that in many instances a canonical basis can be
chosen, which drastically simplifies the solution of the differential equation.
In this paper, an algorithm is presented that computes the transformation to a
canonical basis, starting from some basis that is, for instance, obtained by
the usual integration-by-parts reduction techniques. The algorithm requires the
existence of a rational transformation to a canonical basis, but is otherwise
completely agnostic about the differential equation. In particular, it is
applicable to problems involving multiple scales and allows for a rational
dependence on the dimensional regulator. It is demonstrated that the algorithm
is suitable for current multi-loop calculations by presenting its successful
application to a number of non-trivial examples.Comment: ancillary files provided; published versio
Holographic Ward identities for symmetry breaking in two dimensions

We investigate symmetry breaking in two-dimensional field theories which have
a holographic gravity dual. Being at large N, the Coleman theorem does not hold
and Goldstone bosons are expected. We consider the minimal setup to describe a
conserved current and a charged operator, and we perform holographic
renormalization in order to find the correct Ward identities describing
symmetry breaking. This involves some subtleties related to the different
boundary conditions that a vector can have in the three-dimensional bulk. We
establish which is the correct prescription that yields, after renormalization,
the same Ward identities as in higher dimensions.Comment: 20 pages. v2 comments added. Version to appear in JHE
Two-loop master integrals for the leading QCD corrections to the Higgs
  coupling to a $W$ pair and to the triple gauge couplings $ZWW$ and
  $\gamma^*WW$

We compute the two-loop master integrals required for the leading QCD
corrections to the interaction vertex of a massive neutral boson $X^0$, e.g.
$H,Z$ or $\gamma^{*}$, with a pair of $W$ bosons, mediated by a $SU(2)_L$ quark
doublet composed of one massive and one massless flavor. All the external legs
are allowed to have arbitrary invariant masses. The Magnus exponential is
employed to identify a set of master integrals that, around $d=4$ space-time
dimensions, obey a canonical system of differential equations. The canonical
master integrals are given as a Taylor series in $\epsilon = (4-d)/2$, up to
order four, with coefficients written as combination of Goncharov
polylogarithms, respectively up to weight four. In the context of the Standard
Model, our results are relevant for the mixed EW-QCD corrections to the Higgs
decay to a $W$ pair, as well as to the production channels obtained by
crossing, and to the triple gauge boson vertices $ZWW$ and $\gamma^*WW$.Comment: 42 pages, 5 figures, 2 ancillary file
DC Conductivities from Non-Relativistic Scaling Geometries with Momentum
  Dissipation

We consider a gravitational theory with two Maxwell fields, a dilatonic
scalar and spatially dependent axions. Black brane solutions to this theory are
Lifshitz-like and violate hyperscaling. Working with electrically charged
solutions, we calculate analytically the holographic DC conductivities when
both gauge fields are allowed to fluctuate. We discuss some of the subtleties
associated with relating the horizon to the boundary data, focusing on the role
of Lifshitz asymptotics and the presence of multiple gauge fields. The axionic
scalars lead to momentum dissipation in the dual holographic theory. Finally,
we examine the behavior of the DC conductivities as a function of temperature,
and comment on the cases in which one can obtain a linear resistivity.Comment: 32 pages, 3 figures. Figures and references added. Discussion
  modifie
How to employ $\bar{B}^0_d \to J/\psi(\pi\eta,\bar{K}K)$ decays to
  extract information on $\pi\eta$ scattering

We demonstrate that dispersion theory allows one to deduce crucial
information on $\pi\eta$ scattering from the final-state interactions of the
light mesons visible in the spectral distributions of the decays $\bar{B}^0_d
\to J/\psi(\pi^0\eta,K^+K^-,K^0\bar{K}^0)$. Thus high-quality measurements of
these differential observables are highly desired. The corresponding rates are
predicted to be of the same order of magnitude as those for $\bar{B}^0_d \to
J/\psi\pi^+\pi^-$ measured recently at LHCb, letting the corresponding
measurement appear feasible.Comment: 26 pages, 4 figures; v2: discussion extended, new sec. 3 and app. B,
  as published in JHE
D2-D8 system with massive strings and the Lifshitz spacetimes

The Romans type IIA supergravity allows fundamental strings to have explicit
mass term at the tree level. We show that there exists a (F1,D2,D8) brane
configuration which gives rise to $Lif_4^{(2)}\times {R}^1\times S^5$ vacua
supported by the massive strings. The presence of D8-branes naturally excites
massive fundamental strings. A compactification on circle relates these
Lifshitz massive type-IIA background with the axion-flux $Lif_4^{(2)}\times
{S}^1\times S^5$ vacua in ordinary type-IIB theory. The massive T-duality in
eight dimensions further relates them to yet another
$\widetilde{Lif}_4^{(2)}\times S^1\times S^5$ vacua constituted by (F1,D0,D6)
system in ordinary type IIA theory. The latter vacua after compactification to
four dimensions generate two `distinct' electric charges and a constant
magnetic field, all living over 2-dimensional plane. This somewhat reminds us
of a similar set up in quantum Hall systems.Comment: 19 pages; minor change
Fingerprints of heavy scales in electroweak effective Lagrangians

The couplings of the electroweak effective theory contain information on the
heavy-mass scales which are no-longer present in the low-energy Lagrangian. We
build a general effective Lagrangian, implementing the electroweak chiral
symmetry breaking $SU(2)_L\otimes SU(2)_R\to SU(2)_{L+R}$, which couples the
known particle fields to heavier states with bosonic quantum numbers
$J^P=0^\pm$ and $1^\pm$. We consider colour-singlet heavy fields that are in
singlet or triplet representations of the electroweak group. Integrating out
these heavy scales, we analyze the pattern of low-energy couplings among the
light fields which are generated by the massive states. We adopt a generic
non-linear realization of the electroweak symmetry breaking with a singlet
Higgs, without making any assumption about its possible doublet structure.
Special attention is given to the different possible descriptions of massive
spin-1 fields and the differences arising from naive implementations of these
formalisms, showing their full equivalence once a proper short-distance
behaviour is required.Comment: 57 pages, 1 pdf figure. Version published at JHE
Nonlinear symmetries of black hole entropy in gauged supergravity

Freudenthal duality in N=2, D=4 ungauged supergravity is generated by an
anti-involutive operator that acts on the electromagnetic fluxes, and results
to be a symmetry of the Bekenstein-Hawking entropy. We show that, with a
suitable extension, this duality can be generalized to the abelian gauged case
as well, even in presence of hypermultiplets. By defining Freudenthal duality
along the scalar flow, one can prove that two configurations of charges and
gaugings linked by the Freudenthal operator share the same set of values of the
scalar fields at the black hole horizon. Consequently, Freudenthal duality is
promoted to a nonlinear symmetry of the black hole entropy. We explicitly show
this invariance for the model with prepotential $F=-i X^0 X^1$ and
Fayet-Iliopoulos gauging.Comment: 16 pages, uses jheppub.st
The Cardy limit of the topologically twisted index and black strings in
  AdS$_5$

We evaluate the topologically twisted index of a general four-dimensional
$\mathcal{N} = 1$ gauge theory in the "high-temperature" limit. The index is
the partition function for $\mathcal{N} = 1$ theories on $S^2 \times T^2$, with
a partial topological twist along $S^2$, in the presence of background magnetic
fluxes and fugacities for the global symmetries. We show that the logarithm of
the index is proportional to the conformal anomaly coefficient of the
two-dimensional $\mathcal{N} = (0,2)$ SCFTs obtained from the compactification
on $S^2$. We also present a universal formula for extracting the index from the
four-dimensional conformal anomaly coefficient and its derivatives. We give
examples based on theories whose holographic duals are black strings in type
IIB backgrounds AdS$_5 \times \text{SE}_5$, where SE$_5$ are five-dimensional
Sasaki-Einstein spaces.Comment: 31 pages, V2: minor corrections, refs added, V3: minor corrections,
  published version, V4: few signs correcte