pinecone/core-2020-05-10-deduplication huggingface dataset:
Breit-Wigner approximation for propagators of mixed unstable states

For systems of unstable particles that mix with each other, an approximation
of the fully momentum-dependent propagator matrix is presented in terms of a
sum of simple Breit-Wigner propagators that are multiplied with finite on-shell
wave function normalisation factors. The latter are evaluated at the complex
poles of the propagators. The pole structure of general propagator matrices is
carefully analysed, and it is demonstrated that in the proposed approximation
imaginary parts arising from absorptive parts of loop integrals are properly
taken into account. Applying the formalism to the neutral MSSM Higgs sector
with complex parameters, very good numerical agreement is found between cross
sections based on the full propagators and the corresponding cross sections
based on the described approximation. The proposed approach does not only
technically simplify the treatment of propagators with non-vanishing
off-diagonal contributions, it is shown that it can also facilitate an improved
theoretical prediction of the considered observables via a more precise
implementation of the total widths of the involved particles. It is also
well-suited for the incorporation of interference effects arising from
overlapping resonances.Comment: 44 pages, 13 figures; v2: matches the version to appear in JHEP,
  extended discussion of uncertainty estimate and gauge dependenc
Barnacles and Gravity

Theories with more than one vacuum allow quantum transitions between them,
which may proceed via bubble nucleation; theories with more than two vacua
posses additional decay modes in which the wall of a bubble may further decay.
The instantons which mediate such a process have $O(3)$ symmetry (in four
dimensions, rather than the usual $O(4)$ symmetry of homogeneous vacuum decay),
and have been called `barnacles'; previously they have been studied in flat
space, in the thin wall limit, and this paper extends the analysis to include
gravity. It is found that there are regions of parameter space in which, given
an initial bubble, barnacles are the favoured subsequent decay process, and
that the inclusion of gravity can enlarge this region. The relation to other
heterogeneous vacuum decay scenarios, as well as some of the phenomenological
implications of barnacles are briefly discussed.Comment: 31 pages, 11 figure
On Exceptional Instanton Strings

According to a recent classification of 6d (1,0) theories within F-theory
there are only six "pure" 6d gauge theories which have a UV superconformal
fixed point. The corresponding gauge groups are $SU(3),SO(8),F_4,E_6,E_7$, and
$E_8$. These exceptional models have BPS strings which are also instantons for
the corresponding gauge groups. For $G$ simply-laced, we determine the 2d
$\mathcal{N}=(0,4)$ worldsheet theories of such BPS instanton strings by a
simple geometric engineering argument. These are given by a twisted $S^2$
compactification of the 4d $\mathcal{N}=2$ theories of type $H_2, D_4, E_6,
E_7$ and $E_8$ (and their higher rank generalizations), where the 6d instanton
number is mapped to the rank of the corresponding 4d SCFT. This determines
their anomaly polynomials and, via topological strings, establishes an
interesting relation among the corresponding $T^2 \times S^2$ partition
functions and the Hilbert series for moduli spaces of $G$ instantons. Such
relations allow to bootstrap the corresponding elliptic genera by modularity.
As an example of such procedure, the elliptic genera for a single instanton
string are determined. The same method also fixes the elliptic genus for case
of one $ F_4 $ instanton. These results unveil a rather surprising relation
with the Schur index of the corresponding 4d $\mathcal{N}=2$ models.Comment: 64 pages; v3: version to appear in JHE
Criticality for charged black branes

We show that the inclusion of higher curvature terms in the gravitational
action can lead to phase transitions and critical behaviour for charged black
branes. The higher curvature terms considered here belong to the recently
constructed generalized quasi-topological class [ArXiv: 1703.01631], which
possess a number of interesting properties, such as being ghost-free on
constant curvature backgrounds and non-trivial in four dimensions. We show that
critical behaviour is a generic feature of the black branes in all dimensions
$d \ge 4$, and contextualize the results with a review of the properties of
black branes in Lovelock and quasi-topological gravity, where critical
behaviour is not possible. These results may have interesting implications for
the CFTs dual to this class of theories.Comment: 31 pages, 6 figures. v2: minor typos corrected, references added;
  updated to match published versio
Higgs-Precision Constraints on Colored Naturalness

The presence of weak-scale colored top partners is among the simplest
solutions to the Higgs hierarchy problem and allows for a natural electroweak
scale. We examine the constraints on generic colored top partners coming solely
from their effect on the production and decay rates of the observed Higgs with
a mass of 125 GeV. We use the latest Higgs precision data from the Tevatron and
the LHC as of EPS 2017 to derive the current limits on spin-0, spin-1/2, and
spin-1 colored top partners. We also investigate the expected sensitivity from
the Run 3 and Run 4 of the LHC, as well from possible future electron-positron
and proton-proton colliders, including the ILC, CEPC, FCC-ee, and FCC-hh. We
discuss constraints on top partners in the Minimal Supersymmetric Standard
Model and Little Higgs theories. We also consider various model-building
aspects--multiple top partners, modified couplings between the Higgs and
Standard-Model particles, and non-Standard-Model Higgs sectors--and evaluate
how these weaken the current limits and expected sensitivities. By modifying
other Standard-Model Higgs couplings, we find that the best way to hide
low-mass top partners from current data is through modifications of the
top-Yukawa coupling, although future measurements of top-quark-pair production
in association with a Higgs will extensively probe this possibility. We also
demonstrate that models with multiple top partners can generically avoid
current and future Higgs precision measurements. Nevertheless, some of the
model parameter space can be probed with precision measurements at future
electron-positron colliders of, for example, the e+ e- -> Zh cross section.Comment: 34 pages + appendices and references, 14 figures; added reference
Quantum Information Metric on $\mathbb{R} \times S^{d-1}$

We present a formula for the information metric on $\mathbb{R} \times
{S}^{d-1}$ for a scalar primary operator of integral dimension $\Delta \, (\,\,
> \frac{d+1}{2})$. This formula is checked for various space-time dimensions
$d$ and $\Delta$ in the field theory side. We check the formula in the gravity
side using the holographic setup. We clarify the regularization and
renormalization involved in these computations. We also show that the quantum
information metric of an exactly marginal operator agrees with the leading
order of the interface free energy of the conformal Janus on Euclidean ${S}^d$,
which is checked for $d=2, 3$.Comment: 21 pages, 2 figure
N=2 S-duality Revisited

Using the chiral algebra bootstrap, we revisit the simplest Argyres-Douglas
(AD) generalization of Argyres-Seiberg S-duality. We argue that the exotic AD
superconformal field theory (SCFT), $T_{3,{3\over2}}$, emerging in this duality
splits into a free piece and an interacting piece, T_X, even though this
factorization seems invisible in the Seiberg-Witten (SW) curve derived from the
corresponding M5-brane construction. Without a Lagrangian, an associated
topological field theory, a BPS spectrum, or even an SW curve, we nonetheless
obtain exact information about T_X by bootstrapping its chiral algebra,
chi(T_X), and finding the corresponding vacuum character in terms of Affine
Kac-Moody characters. By a standard 4D/2D correspondence, this result gives us
the Schur index for T_X and, by studying this quantity in the limit of small
S^1, we make contact with a proposed S^1 reduction. Along the way, we discuss
various properties of T_X: as an N=1 theory, it has flavor symmetry
SU(3)XSU(2)XU(1), the central charge of chi(T_X) matches the central charge of
the bc ghosts in bosonic string theory, and its global SU(2) symmetry has a
Witten anomaly. This anomaly does not prevent us from building conformal
manifolds out of arbitrary numbers of T_X theories (giving us a surprisingly
close AD relative of Gaiotto's T_N theories), but it does lead to some open
questions in the context of the chiral algebra / 4D N=2 SCFT correspondence.Comment: 30+10 pages; 4 appendices; 6 figure
Search for new phenomena in a lepton plus high jet multiplicity final
  state with the ATLAS experiment using $\sqrt{s}$ = 13 Tev proton-proton
  collision data

A search for new phenomena in final states characterized by high jet
multiplicity, an isolated lepton (electron or muon) and either zero or at least
three $b$-tagged jets is presented. The search uses 36.1 fb$^{-1}$ of
$\sqrt{s}$ = 13 TeV proton-proton collision data collected by the ATLAS
experiment at the Large Hadron Collider in 2015 and 2016. The dominant sources
of background are estimated using parameterized extrapolations, based on
observables at medium jet multiplicity, to predict the $b$-tagged jet
multiplicity distribution at the higher jet multiplicities used in the search.
No significant excess over the Standard Model expectation is observed and 95%
confidence-level limits are extracted constraining four simplified models of
$R$-parity-violating supersymmetry that feature either gluino or top-squark
pair production. The exclusion limits reach as high as 2.1 TeV in gluino mass
and 1.2 TeV in top-squark mass in the models considered. In addition, an upper
limit is set on the cross-section for Standard Model $t\bar{t}t\bar{t}$
production of 60 fb (6.5 $\times$ the Standard Model prediction) at 95%
confidence level. Finally, model-independent limits are set on the contribution
from new phenomena to the signal-region yields.Comment: 51 pages in total, author list starting page 35, 10 figures, 5
  tables, submitted to JHEP. All figures including auxiliary figures are
  available at
  http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/SUSY-2016-11
Three-form multiplet and supersymmetry breaking

Recently, a nilpotent real scalar superfield $V$ was introduced in
arXiv:1702.02423 as a model for the Goldstino. It contains only two independent
component fields, the Goldstino and the auxiliary $D$-field. Here we first show
that $V$ can equivalently be realised as a constrained three-form superfield.
We demonstrate that every irreducible Goldstino superfield (of which the
Goldstino is the only independent component field) can be realised as a
descendant of $V$ which is invariant under local rescalings $V \to {\rm e}^\tau
V$, where $\tau$ is an arbitrary real scalar superfield. We next propose a new
Goldstino supermultiplet which is described by a nilpotent three-form
superfield $\cal Y$ that is a variant formulation for the nilpotent chiral
superfield, which is often used in off-shell models for spontaneously broken
supergravity. It is shown that the action describing the dynamics of $\cal Y$
may be obtained from a supersymmetric nonlinear $\sigma$-model in the infrared
limit. Unlike $V$, the Goldstino superfield $\cal Y$ contains two independent
auxiliary fields, $F= H+{\rm i} G$, of which $H$ is a scalar and $G$ is the
field strength of a gauge three-form. When $\cal Y$ is coupled to supergravity,
both $H$ and $G$ produce positive contributions to the cosmological constant.
While the contribution from $H$ is uniquely determined by the parameter of the
supersymmetry breaking in the action, the contribution from $G$ is dynamical.Comment: 18 pages; minor correction
Correct Definition of Color Singlet P-Wave Non-Perturbative Matrix
  Element of Heavy Quarkonium Production

Recently we have proved factorization of infrared divergences in NRQCD S-wave
heavy quarkonium production at high energy colliders at all orders in coupling
constant. One of the problem which still exists in the higher order pQCD
calculation of color singlet P-wave heavy quarkonium production/anihillation is
the appearance of non-canceling infrared divergences due to real soft gluons
exchange, although no such infrared divergences are present in the color
singlet S-wave heavy quarkonium. In this paper we find that since the
non-perturbative matrix element of the color singlet P-wave heavy quarkonium
production contains derivative operators, the gauge links are necessary to make
it gauge invariant and be consistent with the factorization of such
non-canceling infrared divergences at all orders in coupling constant.Comment: 18 pages latex, Final Version, Accepted for Publication in JHE
Extracting the mass scale of a second Higgs boson from a deviation in
  $h(125)$ couplings

We investigate the correlation between a possible deviation in the discovered
Higgs boson $h(125)$ couplings from the Standard Model prediction and the mass
scale ($M_{\text{2nd}}$) of the next-to-lightest Higgs boson in models with
non-minimal Higgs sectors. In particular, we comprehensively study a class of
next-to-minimal Higgs sectors which satisfy the electroweak $\rho$ parameter to
be one at tree level. We derive an upper limit on $M_{\text{2nd}}$ by imposing
bounds from perturbative unitarity, vacuum stability, triviality and
electroweak precision data as functions of the deviation in the $hVV$ ($V=W,Z$)
couplings. Furthermore, we discuss the complementarity between these bounds and
the current LHC data, e.g., by considering direct searches for additional Higgs
bosons and indirect constraints arising from the measured $h(125)$ signal
strengths.Comment: 37 pages, 36 figure
E(lementary) Strings in Six-Dimensional Heterotic F-Theory

Using E-strings, we can analyze not only six-dimensional superconformal field
theories but also probe vacua of non-perturabative heterotic string. We study
strings made of D3-branes wrapped on various two-cycles in the global F-theory
setup. We claim that E-strings are elementary in the sense that various
combinations of E-strings can form M-strings as well as heterotic strings and
new kind of strings, called G-strings. Using them, we show that emissions and
combinations of heterotic small instantons generate most of known
six-dimensional superconformal theories, their affinizations and little string
theories. Taking account of global structure of compact internal geometry, we
also show that special combinations of E-strings play an important role in
constructing six-dimensional theories of $D$- and $E$-types. We check global
consistency conditions from anomaly cancellation conditions, both from
five-branes and strings, and show that they are given in terms of elementary
E-string combinations.Comment: 58 pages, 16 figures; v2. version to appear in JHE
Baryonic Higgs at the LHC

We investigate the possible collider signatures of a new Higgs in simple
extensions of the Standard Model where baryon number is a local symmetry
spontaneously broken at the low scale. We refer to this new Higgs as "Baryonic
Higgs". This Higgs has peculiar properties since it can decay into all Standard
Model particles, the leptophobic gauge boson, and the vector-like quarks
present in these theories to ensure anomaly cancellation. We investigate in
detail the constraints from the $\gamma \gamma$, $Z \gamma$, $Z Z$, and $W W$
searches at the Large Hadron Collider, needed to find a lower bound on the
scale at which baryon number is spontaneously broken. The di-photon channel
turns out to be a very sensitive probe in the case of small scalar mixing and
can severely constrain the baryonic scale. We also study the properties of the
leptophobic gauge boson in order to understand the testability of these
theories at the LHC.Comment: 20 pages, 9 figures; minor corrections, to appear in JHE
Natural Fermion Hierarchies from Random Yukawa Couplings

The Standard Model of particle physics requires Yukawa matrices with
eigenval- ues that differ by orders of magnitude. We propose a novel way to
explain this fact without any small or large parameters. The mechanism is based
on the observation that products of matrices of random order one-numbers have
hierarchical spectra. The same mechanism can easily account for the
hierarchical structure of the quark mixing matrix.Comment: 9 pages. v2: Extended and improved discussion on CKM matrix.
  References added. Matches published versio
Effective field theory for dissipative fluids (II): classical limit,
  dynamical KMS symmetry and entropy current

In this paper we further develop the fluctuating hydrodynamics proposed in
arXiv:1511.03646 in a number of ways. We first work out in detail the classical
limit of the hydrodynamical action, which exhibits many simplifications. In
particular, this enables a transparent formulation of the action in physical
spacetime in the presence of arbitrary external fields. It also helps to
clarify issues related to field redefinitions and frame choices. We then
propose that the action is invariant under a $Z_2$ symmetry to which we refer
as the dynamical KMS symmetry. The dynamical KMS symmetry is physically
equivalent to the previously proposed local KMS condition in the classical
limit, but is more convenient to implement and more general. It is applicable
to any states in local equilibrium rather than just thermal density matrix
perturbed by external background fields. Finally we elaborate the formulation
for a conformal fluid, which contains some new features, and work out the
explicit form of the entropy current to second order in derivatives for a
neutral conformal fluid.Comment: 49+8 pages, 1 figure. v2: references added, minor clarification
Entanglement branes in a two-dimensional string theory

What is the meaning of entanglement in a theory of extended objects such as
strings? To address this question we consider the spatial entanglement between
two intervals in the Gross-Taylor model, the string theory dual to
two-dimensional Yang-Mills theory at large $N$. The string diagrams that
contribute to the entanglement entropy describe open strings with endpoints
anchored to the entangling surface, as first argued by Susskind. We develop a
canonical theory of these open strings, and describe how closed strings are
divided into open strings at the level of the Hilbert space. We derive the
Modular hamiltonian for the Hartle-Hawking state and show that the
corresponding reduced density matrix describes a thermal ensemble of open
strings ending on an object at the entangling surface that we call an E-brane.Comment: 37 pages, 12 figures. v3: Modified title and abstrac
On the Light Massive Flavor Dependence of the Large Order Asymptotic
  Behavior and the Ambiguity of the Pole Mass

We provide a systematic renormalization group formalism for the mass effects
in the relation of the pole mass $m_Q^{\rm pole}$ and short-distance masses
such as the $\overline{\rm MS}$ mass $\overline{m}_Q$ of a heavy quark $Q$,
coming from virtual loop insertions of massive quarks lighter than $Q$. The
formalism reflects the constraints from heavy quark symmetry and entails a
combined matching and evolution procedure that allows to disentangle and
successively integrate out the corrections coming from the lighter massive
quarks and the momentum regions between them and to precisely control the large
order asymptotic behavior. With the formalism we systematically sum logarithms
of ratios of the lighter quark masses and $m_Q$, relate the QCD corrections for
different external heavy quarks to each other, predict the ${\cal
O}(\alpha_s^4)$ virtual quark mass corrections in the pole-$\overline{\rm MS}$
mass relation, calculate the pole mass differences for the top, bottom and
charm quarks with a precision of around $20$ MeV and analyze the decoupling of
the lighter massive quark flavors at large orders. The summation of logarithms
is most relevant for the top quark pole mass $m_t^{\rm pole}$, where the
hierarchy to the bottom and charm quarks is large. We determine the ambiguity
of the pole mass for top, bottom and charm quarks in different scenarios with
massive or massless bottom and charm quarks in a way consistent with heavy
quark symmetry, and we find that it is $250$ MeV. The ambiguity is larger than
current projections for the precision of top quark mass measurements in the
high-luminosity phase of the LHC.Comment: 45 pages + appendix, 6 figures, v2: journal versio
Bell's Inequality and Entanglement in Qubits

We propose an alternative evaluation of quantum entanglement by measuring the
maximum violation of the Bell's inequality without performing a partial trace
operation. This proposal is demonstrated by bridging the maximum violation of
the Bell's inequality and the concurrence of a pure state in an $n$-qubit
system, in which one subsystem only contains one qubit and the state is a
linear combination of two product states. We apply this relation to the ground
states of four qubits in the Wen-Plaquette model and show that they are
maximally entangled. A topological entanglement entropy of the Wen-Plaquette
model could be obtained by relating the upper bound of the maximum violation of
the Bell's inequality to the concurrences of a pure state with respect to
different bipartitions.Comment: 10 page
Collider constraints and new tests of color octet vectors

We analyze the collider sensitivity for new colored resonances in $t\bar{t}$,
$b \bar{b}$, and $jj$ final states. While searches in the single production
channel are model-dependent, the pair production rate is model independent and
the existing $(JJ)(JJ)$ and $4t$ searches impose strong constraints on the
relevant branching fractions, where $J = j$ or $b$. We point out the missing,
complementary searches in the mixed decay modes, $t\bar{t}(jj)$,
$t\bar{t}(b\bar{b})$, and $(b\bar{b})(jj)$. We propose analysis strategies for
the $t\bar{t}(jj)$ and $t\bar{t}(b\bar{b})$ decays and find their sensivity
surpasses that of existing searches when the decay widths to tops and light
jets are comparable. If no other decays are present, collective lower limits on
the resonance mass can be set at 1.5~TeV using 37~fb$^{-1}$ of 13~TeV data.Comment: 22 pages, 3 figures, 2 table
A Numerical Approach to Virasoro Blocks and the Information Paradox

We chart the breakdown of semiclassical gravity by analyzing the Virasoro
conformal blocks to high numerical precision, focusing on the heavy-light limit
corresponding to a light probe propagating in a BTZ black hole background. In
the Lorentzian regime, we find empirically that the initial exponential
time-dependence of the blocks transitions to a universal $t^{-\frac{3}{2}}$
power-law decay. For the vacuum block the transition occurs at $t \approx
\frac{\pi c}{6 h_L}$, confirming analytic predictions. In the Euclidean regime,
due to Stokes phenomena the naive semiclassical approximation fails completely
in a finite region enclosing the `forbidden singularities'. We emphasize that
limitations on the reconstruction of a local bulk should ultimately stem from
distinctions between semiclassical and exact correlators.Comment: 45 pages, 23 figure