pinecone/core-2020-05-10-deduplication huggingface dataset:
A new scalar resonance at 750 GeV: Towards a proof of concept in favor
  of strongly interacting theories

We interpret the recently observed excess in diphoton invariant mass as a new
spin-0 resonant particle. On the theoretical ground, an interesting question is
whether this new scalar resonance belongs to a strongly coupled sector or a
well-defined weakly coupled theory. A possible UV-completion that has been
widely considered in literature is based on the existence of new vector-like
fermions whose loop contributions---Yukawa-coupled to the new
resonance---explain the observed signal rate. The large total width
preliminarily suggested by data seems to favor a large Yukawa coupling, at the
border of a healthy perturbative definition. This potential problem can be
fixed by introducing multiple vector-like fermions or large electric charges,
bringing back the theory to a weakly coupled regime. However, this solution
risks to be only a low-energy mirage: Large multiplicity or electric charge can
dangerously reintroduce the strong regime by modifying the renormalization
group running of the dimensionless couplings. This issue is also tightly
related to the (in)stability of the scalar potential. First, we study---in the
theoretical setup described above---the parametric behavior of the diphoton
signal rate, total width, and one-loop $\beta$ functions. Then, we numerically
solve the renormalization group equations, taking into account the observed
diphoton signal rate and total width, to investigate the fate of the weakly
coupled theory. We find that---with the only exception of few fine-tuned
directions---weakly coupled interpretations of the excess are brought back to a
strongly coupled regime if the running is taken into account.Comment: 32 pages, 38 figures, version appeared in JHEP, Fig.1 and 4 revised,
  references added, new section V.C adde
750 GeV Diphotons and Supersymmetric Grand Unification

We investigate the 750 GeV diphoton excess in terms of supersymmetric models
which preserve grand unification in the ultraviolet. We show that minimal
extensions of the MSSM by a singlet and a vector-like 5-plet or 10-plet of
SU(5) can explain the observed signal while remaining perturbative up to the
GUT scale. Different from previous analyses we rely on light sfermions in the
loops which - compared to the analog non-supersymmetric models - enhance the
diphoton cross section by up to a factor of seven. While the resonance decay
width is narrow, mass splitting of the scalar and pseudoscalar components may
result in a double resonance. We perform a likelihood analysis on the ATLAS and
CMS data to show that the significance of the diphoton excess increases from
3.3 sigma (single narrow resonance) to 3.9 sigma for the double resonance. We
also provide signal predictions in other diboson channels to be tested at
LHC-13.Comment: 20 pages, 6 figure
On quantum corrections in higher-spin theory in flat space

We consider an interacting theory of an infinite tower of massless
higher-spin fields in flat space with cubic vertices and their coupling
constants found previously by Metsaev. We compute the one-loop bubble diagram
part of the self-energy of the spin 0 member of the tower by summing up all
higher-spin loop contributions. We find that the result contains an
exponentially UV divergent part and we discuss how it could be cancelled by a
tadpole contribution depending on yet to be determined quartic interaction
vertex. We also compute the tree-level four-scalar scattering amplitude due to
all higher-spin exchanges and discuss its inconsistency with the BCFW
constructibility condition. We comment on possible relation to similar
computations in AdS background in connection with AdS/CFT.Comment: 34 pages, minor corrections and references adde
Induced Gravity II: Grand Unification

As an illustration of a renormalizable, asymptotically-free model of induced
gravity, we consider an $SO(10)$ gauge theory interacting with a real scalar
multiplet in the adjoint representation. We show that dimensional transmutation
can occur, spontaneously breaking $SO(10)$ to $SU(5){\otimes}U(1),$ while
inducing the Planck mass and a positive cosmological constant, all proportional
to the same scale $v$. All mass ratios are functions of the values of coupling
constants at that scale. Below this scale (at which the Big Bang may occur),
the model takes the usual form of Einstein-Hilbert gravity in de Sitter space
plus calculable corrections. We show that there exist regions of parameter
space in which the breaking results in a local minimum of the effective action,
and a {\bf positive} dilaton $(\hbox{mass})^2$ from two-loop corrections
associated with the conformal anomaly. Furthermore, unlike the singlet case we
considered previously, some minima lie within the basin of attraction of the
ultraviolet fixed point. Moreover, the asymptotic behavior of the coupling
constants also lie within the range of convergence of the Euclidean path
integral, so there is hope that there will be candidates for sensible vacua.
Although open questions remain concerning unitarity of all such renormalizable
models of gravity, it is not obvious that, in curved backgrounds such as those
considered here, unitarity is violated. In any case, any violation that may
remain will be suppressed by inverse powers of the reduced Planck mass.Comment: 44 pages, 5 figures, 2 tables. v2 has new discussion concerning
  stability of SSB plus related appendix. Additional references added. v3 is
  version to be published; contains minor revision
The String BCJ Relations Revisited and Extended Recurrence relations of
  Nonrelativistic String Scattering Amplitudes

We review and extend high energy string BCJ relations in both the fixed angle
and Regge regimes. We then give an explicit proof of four point string BCJ
relations for all energy. This calculation provides an alternative proof of the
one based on monodromy of integration in string amplitude calculation. In
addition, we calculate both s-t and t-u channel nonrelativistic low energy
string scattering amplitudes of three tachyons and one leading trojectory
string state at arbitrary mass levels. We discover that the mass and spin
dependent nonrelativistic string BCJ relations can be expressed in terms of
Gauss hypergeometry functions. As an application, for each fixed mass level N,
we derive extended recurrence relations among nonrelativistic low energy string
scattering amplitudes of string states with different spins and different
channels.Comment: 22 pages, v2:23 pages. Section IV.B added; Refs [30],[31] added. To
  appear in JHE
Indirect Constraints on the Scalar Di-Photon Resonance at the LHC

Motivated by the tantalizing excesses recently reported in the di-photon
invariant mass spectrum at the LHC, we scrutinize some implications of scalar
di-photon resonances in high energy proton-proton collisions. In particular,
indications of a large width impose several challenges for model building. We
show how calculability and unitarity considerations severely limit possible
perturbative realizations of such a signal and propose a simple criterion that
can be adapted to any renormalizable model. Furthermore, we discuss
correlations between a di-photon excess and precision observables, including
the anomalous magnetic and electric dipole moments of quarks and leptons,
neutral meson oscillations and radiative flavor changing neutral current
mediated decays of heavy leptons and hadrons. We find that existing searches
and measurements significantly constrain the possibilities for a scalar
resonance decaying into final states involving Standard Model fermions. We
propose future search strategies which could elucidate some remaining currently
unconstrained decay channels and discuss possible correlations between the
di-photon excess and several recently reported flavor anomalies, showing that
the latter can be addressed in a new incarnation of a gauged $U(1)^\prime$
model, with the di-photon resonance being the physical remnant of the
$U(1)^\prime$-breaking field.Comment: 34 pages, 4 figures. Minor changes, version accepted in JHE
Relativistic magnetohydrodynamics

We present the equations of relativistic hydrodynamics coupled to dynamical
electromagnetic fields, including the effects of polarization, electric fields,
and the derivative expansion. We enumerate the transport coefficients at
leading order in derivatives, including electrical conductivities, viscosities,
and thermodynamic coefficients. We find the constraints on transport
coefficients due to the positivity of entropy production, and derive the
corresponding Kubo formulas. For the neutral state in a magnetic field, small
fluctuations include Alfven waves, magnetosonic waves, and the dissipative
modes. For the state with a non-zero dynamical charge density in a magnetic
field, plasma oscillations gap out all propagating modes, except for
Alfven-like waves with a quadratic dispersion relation. We relate the transport
coefficients in the "conventional" magnetohydrodynamics (formulated using
Maxwell's equations in matter) to those in the "dual" version of
magnetohydrodynamics (formulated using the conserved magnetic flux).Comment: 42 page
Light Weakly Coupled Axial Forces: Models, Constraints, and Projections

We investigate the landscape of constraints on MeV-GeV scale, hidden U(1)
forces with nonzero axial-vector couplings to Standard Model fermions. While
the purely vector-coupled dark photon, which may arise from kinetic mixing, is
a well-motivated scenario, several MeV-scale anomalies motivate a theory with
axial couplings which can be UV-completed consistent with Standard Model gauge
invariance. Moreover, existing constraints on dark photons depend on products
of various combinations of axial and vector couplings, making it difficult to
isolate the effects of axial couplings for particular flavors of SM fermions.
We present a representative renormalizable, UV-complete model of a dark photon
with adjustable axial and vector couplings, discuss its general features, and
show how some UV constraints may be relaxed in a model with nonrenormalizable
Yukawa couplings at the expense of fine-tuning. We survey the existing
parameter space and the projected reach of planned experiments, briefly
commenting on the relevance of the allowed parameter space to low-energy
anomalies in pi^0 and 8-Be* decay.Comment: 30 pages, 5 figures, 4 tables. v2: format changed to JHEP, typos
  fixed, references adde
Trilinear-Augmented Gaugino Mediation

We consider a gaugino-mediated supersymmetry breaking scenario where in
addition to the gauginos the Higgs fields couple directly to the field that
breaks supersymmetry. This yields non-vanishing trilinear scalar couplings in
general, which can lead to large mixing in the stop sector providing a
sufficiently large Higgs mass. Using the most recent release of FeynHiggs, we
show the implications on the parameter space. Assuming a gravitino LSP, we find
allowed points with a neutralino, sneutrino or stau NLSP. We test these points
against the results of Run 1 of the LHC, considering in particular searches for
heavy stable charged particles.Comment: 13 pages + references, 4 figures, v4: corrected plot labels in figs.
  1-
Prompt neutrino fluxes in the atmosphere with PROSA parton distribution
  functions

Effects on atmospheric prompt neutrino fluxes of present uncertainties
affecting the nucleon composition are studied by using the PROSA fit to parton
distribution functions (PDFs). The PROSA fit extends the precision of the PDFs
to low x, which is the kinematic region of relevance for high-energy neutrino
production, by taking into account LHCb data on charm and bottom
hadroproduction. In the range of neutrino energies explored by present Very
Large Volume Neutrino Telescopes, it is found that PDF uncertainties are far
smaller with respect to those due to renormalization and factorization scale
variation and to assumptions on the cosmic ray composition, which at present
dominate and limit our knowledge of prompt neutrino fluxes. A discussion is
presented on how these uncertainties affect the expected number of atmospheric
prompt neutrino events in the analysis of high-energy events characterized by
interaction vertices fully contained within the instrumented volume of the
detector, performed by the IceCube collaboration.Comment: 36 pages, 17 figures, 1 tabl
Spectral weight and spatially modulated instabilities in holographic
  superfluids

Free fermions form a Fermi surface, which results in non-zero spectral weight
at low energy and finite wavevector. In this work, we find similar features in
holographic phases dual to strongly coupled quantum superfluid matter. At zero
temperature, the phases we consider exhibit semi-local criticality in the IR
and all the charge is carried by the scalar condensate outside the black hole
horizon. Depending on the value taken by the IR critical exponents, we find
Fermi surfaces in the transverse sector, Fermi shells in the longitudinal
sector or no spectral weight at all. When there is non-zero transverse spectral
weight, the IR can be subject to an instability at finite wavevector, the
endpoint of which is likely a spatially modulated phase.Comment: v2: references added and minor edits, published versio
Deep-learning Top Taggers or The End of QCD?

Machine learning based on convolutional neural networks can be used to study
jet images from the LHC. Top tagging in fat jets offers a well-defined
framework to establish our DeepTop approach and compare its performance to
QCD-based top taggers. We first optimize a network architecture to identify top
quarks in Monte Carlo simulations of the Standard Model production channel.
Using standard fat jets we then compare its performance to a multivariate
QCD-based top tagger. We find that both approaches lead to comparable
performance, establishing convolutional networks as a promising new approach
for multivariate hypothesis-based top tagging.Comment: Version published in JHE
The Evolution of Meson Masses in a Strong Magnetic Field

Spectra of $q \bar{q}$ hadrons are investigated in the framework of the
Hamiltonian obtained from the relativistic path integral in external
homogeneous magnetic field. The spectra of all 12 spin-isospin s-wave states,
generated by $\pi$ and $\rho$ mesons with different spin projections, are
studied both analytically and numerically on the lattice as functions of
(magnetic field) $eB$. Results are in agreement and demonstrate three types of
behavior, with characteristic splittings predicted by the theory.Comment: 29 pages, 7 figures, 1 tabl
On Complexity for Higher Derivative Gravities

Using "complexity=action" proposal we study complexity growth of certain
gravitational theories containing higher derivative terms. These include
critical gravity in diverse dimensions. One observes that the complexity growth
for neutral black holes saturates the proposed bound when the results are
written in terms of physical quantities of the model. We will also study
effects of shock wave to the complexity growth where we find that the presence
of massive spin-2 mode slows down the rate of growth.Comment: 18 pages, 3 figures, journal versio
Purely flavor-changing Z' bosons and where they might hide

A plethora of ultraviolet completions of the Standard Model have extra U(1)
gauge symmetries. In general, the associated massive $Z^\prime$ gauge boson can
mediate flavor-changing neutral current processes at tree level. We consider a
situation where the $Z^\prime$ boson couples solely via flavor-changing
interactions to quarks and leptons. In this scenario the model parameter space
is, in general, quite well constrained by existing flavor bounds. However, we
argue that cancellation effects shelter islands in parameter space from strong
flavor constraints and that these can be probed by multipurpose collider
experiments like ATLAS or CMS as well as LHCb in upcoming runs at the LHC. In
still allowed regions of parameter space these scenarios may help to explain
the current tension between theory and experiment of $(g-2)_\mu$ as well as a
small anomaly in $\tau$ decays.Comment: 44 pages, 22 figures; v2: Corrected factor of -1, updated references,
  improved discussion of tau decays; v3: Minor corrections, further extended
  discussion of tau decay
Projectivity of Planar Zeros in Field and String Theory Amplitudes

We study the projective properties of planar zeros of tree-level scattering
amplitudes in various theories. Whereas for pure scalar field theories we find
that the planar zeros of the five-point amplitude do not enjoy projective
invariance, coupling scalars to gauge fields gives rise to tree-level
amplitudes whose planar zeros are determined by homogeneous polynomials in the
stereographic coordinates labelling the direction of flight of the outgoing
particles. In the case of pure gauge theories, this projective structure is
generically destroyed if string corrections are taken into account. Scattering
amplitudes of two scalars with graviton emission vanish exactly in the planar
limit, whereas planar graviton amplitudes are zero for helicity violating
configurations. These results are corrected by string effects, computed using
the single-valued projection, which render the planar amplitude nonzero.
Finally, we discuss how the structure of planar zeros can be derived from the
soft limit behavior of the scattering amplitudes.Comment: 39 page, 5 figures. v2: typos corrected. It matches the version
  published in Journal of High Energy Physic
Integrable Lambda Models And Chern-Simons Theories

In this note we reveal a connection between the phase space of lambda models
on $S^{1}\times \mathbb{R}$ and the phase space of double Chern-Simons theories
on $D\times \mathbb{R}$ and explain in the process the origin of the
non-ultralocality of the Maillet bracket, which emerges as a boundary algebra.
In particular, this means that the (classical) $AdS_{5}\times S^{5}$ lambda
model can be understood as a double Chern-Simons theory defined on the Lie
superalgebra $\mathfrak{psu}(2,2|4)$ after a proper dependence of the spectral
parameter is introduced. This offers a possibility for avoiding the use of the
problematic non-ultralocal Poisson algebras that preclude the introduction of
lattice regularizations and the application of the QISM to string sigma models.
The utility of the equivalence at the quantum level is, however, still to be
explored.Comment: 27 pages. Published versio
Resonant slepton production and right sneutrino dark matter in
  left-right supersymmetry

Right-handed sneutrinos are natural components of left-right symmetric
supersymmetric models where the gauge sector is extended to include
right-handed weak interactions. Unlike in other models where right-handed
sneutrinos are gauge singlets, here the right sneutrino is part of a doublet
and could be a dark matter candidate whose annihilation proceeds via gauge
interactions. We investigate this possibility, and find that relic density,
low-energy observable and direct supersymmetry search constraints can be
satisfied when the lightest supersymmetric particle is a right-handed
sneutrino. We introduce benchmarks for left-right supersymmetric realizations
where either a sneutrino or a neutralino is the lightest superpartner. We then
study the LHC signals arising through resonant right-handed slepton production
via a $W_R$ gauge-boson exchange that lead to final states enriched in leptons,
additionally containing a large amount of missing transverse momentum, and
featuring a low jet multiplicity. We find that such a resonant production would
boost the chances of discovering these weakly interacting supersymmetric
particles for a mass range extending beyond 1 TeV already with a luminosity of
100 fb$^{-1}$. Finally, we compare sneutrino versus neutralino scenarios, and
comment on differences with other sneutrino dark matter models.Comment: 29 pages, 5 figures, revised versio
$g_\mu-2$ from Vector-Like Leptons in Warped Space

The experimental value of the anomalous magnetic moment of the muon, as well
as the LHCb anomalies, point towards new physics coupled non-universally to
muons and electrons. Working in extra dimensional theories, which solve the
electroweak hierarchy problem with a warped metric, strongly deformed with
respect to the AdS$_5$ geometry at the infra-red brane, the LHCb anomalies can
be solved by imposing that the bottom and the muon have a sizable amount of
compositeness, while the electron is mainly elementary. Using this set-up as
starting point we have proven that extra physics has to be introduced to
describe the anomalous magnetic moment of the muon. We have proven that this
job is done by a set of vector-like leptons, mixed with the physical muon
through Yukawa interactions, and with a high degree of compositeness. The
theory is consistent with all electroweak indirect, direct and theoretical
constraints, the most sensitive ones being the modification of the
$Z\bar\mu\mu$ coupling, oblique observables and constraints on the stability of
the electroweak minimum. They impose lower bounds on the compositeness
($c\lesssim 0.37$) and on the mass of the lightest vector-like lepton ($\gtrsim
270$ GeV). Vector-like leptons could be easily produced in Drell-Yan processes
at the LHC and detected at $\sqrt{s}=13$ TeV.Comment: 42 pages, 15 figures; v2 added reference
The Observer's Ghost: a field-space connection-form and its application
  to gauge theories and general relativity

We introduce a functional covariant differential as a tool for studying field
space geometry in a manifestly covariant way. We then touch upon its role in
gauge theories and general relativity over bounded regions, and in BRST
symmetry. Due to the Gribov problem, we argue that our formalism ---allowing
for a non-vanishing functional curvature---is necessary for a global treatment
of gauge-invariance in field space. We conclude by suggesting that the
structures we introduce satisfactorily implement the notion of a
(non-asymptotic) observer in gauge theories and general relativity.Comment: 17 pages + appendix and references v2 includes more discussion on the
  meaning of the field space connection in the path integra
Towards a new paradigm for quark-lepton unification

The quark and lepton mass patterns upset their naive unification. In this
paper, a new approach to solve this problem is proposed. Model-independently,
we find that a successful unification can be achieved. A mechanism is
identified by which the large top quark mass renders its third-generation
leptonic partner very light. This state is thus identified with the electron.
We then provide a generic dynamical implementation of this mechanism, using
tree-level exchanges of vector leptons to relate the quark and lepton flavor
structures. In a supersymmetric context, this same mechanism splits the squark
masses, and third generation squarks end up much lighter than the others.
Finally, the implementation of this mechanism in SU(5) GUT permits to avoid
introducing any flavor structure beyond the two minimal Yukawa couplings,
ensuring the absence of unknown mixing matrices and their potentially large
impact on FCNC.Comment: 31 pages, 5 figure
O(alpha_s alpha_t) (non)decoupling effects within the top-sector of the
  MSSM

In this paper we compute the $\mathcal{O}(\alpha_s \alpha_t)$ threshold
corrections to the running strong coupling constant, the top-Yukawa coupling
and the top-quark mass within the MSSM. These parameters present a
non-decoupling behaviour with the supersymmetry scale $M_{\rm SUSY}$. Our
numerical analysis shows that the mixed QCD-Yukawa corrections can amount to
few GeV for the running top-quark mass and range at the percent level for the
top-Yukawa coupling.Comment: References added; new lines in the plots displayed; more details
  about the calculation include