pinecone/core-2020-05-10-deduplication huggingface dataset:
On Fine Structure of Strings: The Universal Correction to the Veneziano
  Amplitude

We consider theories of weakly interacting higher spin particles in flat
spacetime. We focus on the four-point scattering amplitude at high energies and
imaginary scattering angles. The leading asymptotic of the amplitude in this
regime is universal and equal to the corresponding limit of the Veneziano
amplitude. In this paper, we find that the first sub-leading correction to this
asymptotic is universal as well. We compute the correction using a model of
relativistic strings with massive endpoints. We argue that it is unique using
holography, effective theory of long strings and bootstrap techniques.Comment: 54 pages, 5 figure
Nonlocal Quantum Effective Actions in Weyl-Flat Spacetimes

Virtual massless particles in quantum loops lead to nonlocal effects which
can have interesting consequences, for example, for primordial magnetogenesis
in cosmology or for computing finite $N$ corrections in holography. We describe
how the quantum effective actions summarizing these effects can be computed
efficiently for Weyl-flat metrics by integrating the Weyl anomaly or,
equivalently, the local renormalization group equation. This method relies only
on the local Schwinger-DeWitt expansion of the heat kernel and allows for a
re-summation of leading large logarithms in situations where the Weyl factor
changes by several e-foldings. As an illustration, we obtain the quantum
effective action for the Yang-Mills field coupled to massless matter, and the
self-interacting massless scalar field. Our action reduces to the nonlocal
action obtained using the Barvinsky-Vilkovisky covariant perturbation theory in
the regime $R^{2} \ll \nabla^{2} R $ for a typical curvature scale $R$, but has
a greater range of validity effectively re-summing the covariant perturbation
theory to all orders in curvatures. In particular, it is applicable also in the
opposite regime $R^{2} \gg \nabla^{2} R$, which is often of interest in
cosmology.Comment: 24 page
Probing light top partners with CP violation

We investigate CP-violating effects induced by light top partners in
composite Higgs theories. We find that sizable contributions to the dipole
moments of the light SM quarks and leptons are generically generated at the
two-loop level through Barr-Zee-type diagrams. The present constraints on the
electron and neutron electric dipole moments translate into bounds on top
partner masses of order few TeV and are competitive with the reach of LHC
direct searches. Interestingly, we find that CP-violation effects are sensitive
to the same operators that control top partner single production. Near-future
improvements in the determination of the electron dipole moment will extend the
reach on top partner masses beyond the 5 - 10 TeV range.Comment: 31 pages, 10 figure
Mellin Bootstrap for Scalars in Generic Dimension

We use the recently developed framework of the Mellin bootstrap to study
perturbatively free scalar CFTs in arbitrary dimensions. This approach uses the
crossing-symmetric Mellin space formulation of correlation functions to
generate algebraic bootstrap equations by demanding that only physical
operators contribute to the OPE. We find that there are no perturbatively
interacting CFTs with only fundamental scalars in $d>6$ dimensions (to at least
second order in the perturbation). Our results can be seen as a modest step
towards understanding the space of interacting CFTs in $d>6$ and are consistent
with the intuition that no such CFTs exist.Comment: 11 pages + appendices. v2: references added, few minor revisions;
  published versio
Solitons and black hole in shift symmetric scalar-tensor gravity with
  cosmological constant

We demonstrate the existence of static, spherically symmetric globally
regular, i.e. solitonic solutions of a shift-symmetric scalar-tensor gravity
model with negative cosmological constant. The norm of the Noether current
associated to the shift symmetry is finite in the full space-time. We also
discuss the corresponding black hole solutions and demonstrate that the
interplay between the scalar-tensor coupling and the cosmological constant
leads to the existence of new branches of solutions. To linear order in the
scalar-tensor coupling, the asymptotic space-time corresponds to an Anti-de
Sitter space-time with a non-trivial scalar field on its conformal boundary.
This allows the interpretation of our solutions in the context of the AdS/CFT
correspondence. Finally, we demonstrate that - for physically relevant, small
values of the scalar-tensor coupling - solutions with positive cosmological
constant do not exist in our model
Massive and Massless Spin-2 Scattering and Asymptotic Superluminality

We constrain theories of a massive spin-2 particle coupled to a massless
spin-2 particle by demanding the absence of a time advance in eikonal
scattering. This is an $S$-matrix consideration that leads to model-independent
constraints on the cubic vertices present in the theory. Of the possible cubic
vertices for the two spin-2 particles, the requirement of subluminality leaves
a particular linear combination of cubic vertices of the Einstein--Hilbert
type. Either the cubic vertices must appear in this combination or new physics
must enter at a scale parametrically the same as the mass of the massive spin-2
field. These conclusions imply that there is a one-parameter family of
ghost-free bimetric theories of gravity that are consistent with subluminal
scattering. When both particles couple to additional matter, subluminality
places additional constraints on the matter couplings. We additionally
reproduce these constraints by considering classical scattering off of a
shockwave background in the ghost-free bimetric theory.Comment: 41 pages, 2 figures, v2: matches journal versio
Surface energy of the one-dimensional supersymmetric $t-J$ model with
  unparallel boundary fields

We investigate the thermodynamic limit of the exact solution, which is given
by an inhomogeneous $T-Q$ relation, of the one-dimensional supersymmetric $t-J$
model with unparallel boundary magnetic fields. It is shown that the
contribution of the inhomogeneous term at the ground state satisfies the
$L^{-1}$ scaling law, where $L$ is the system-size. This fact enables us to
calculate the surface (or boundary) energy of the system. The method used in
this paper can be generalized to study the thermodynamic limit and surface
energy of other models related to rational R-matrices.Comment: published version, 18 pages, 5 figures, 1 tabl
From Euclidean Sources to Lorentzian Spacetimes in Holographic Conformal
  Field Theories

We consider states of holographic conformal field theories constructed by
adding sources for local operators in the Euclidean path integral, with the aim
of investigating the extent to which arbitrary bulk coherent states can be
represented by such Euclidean path-integrals in the CFT. We construct the
associated dual Lorentzian spacetimes perturbatively in the sources. Extending
earlier work, we provide explicit formulae for the Lorentzian fields to first
order in the sources for general scalar field and metric perturbations in
arbitrary dimensions. We check the results by holographically computing the
Lorentzian one-point functions for the sourced operators and comparing with a
direct CFT calculation. We present evidence that at the linearized level,
arbitrary bulk initial data profiles can be generated by an appropriate choice
of Euclidean sources. However, in order to produce initial data that is very
localized, the amplitude must be taken small at the same time otherwise the
required sources diverge, invalidating the perturbative approach.Comment: 36 pages, 3 figure
Holographic meson decays via worldsheet instantons.

We study meson decays using instanton methods in two string models. The first model is the old string model in flat space which combines strings and massive particles and the second is the holographic, Sakai-Sugimoto model. Using the old string model, we reproduce the QCD formula for the probability of splitting of the QCD flux tube derived by Casher-Neuberger-Nussinov (CNN). In the holographic model we construct a string worldsheet instanton which interpolates between a single and double string configuration, which determines the decay from one to two dual mesonic particles. The resulting probability for meson decay incorporates both the effects of finite meson size as well as back-reaction of the produced quarks on the QCD flux tube. In the limit of very large strings the probability for a split reduces to the CNN formula. A byproduct of our analysis is the analysis of the moduli space of a generic double concentric Wilson loop with circles which are separated in the holographic direction of the confining background
Consequences of minimal seesaw with complex $\mu\tau$ antisymmetry of
  neutrinos

We propose a complex extension of $\mu\tau$ permutation antisymmetry in the
neutrino Majorana matrix $M_\nu$. The latter can be realized for the Lagrangian
by appropriate CP transformations on the neutrino fields. The resultant form of
$M_\nu$ is shown to be simply related to that with a complex (CP) extension of
$\mu\tau$ permutation symmetry, with identical phenomenological consequences,
though their group theoretic origins are quite different. We investigate those
consequences in detail for the minimal seesaw induced by two strongly
hierarchical right-chiral neutrinos $N_1$ and $N_2$ with the result that the
Dirac phase is maximal while the two Majorana phases are either 0 or $\pi$. We
further provide an uptodate discussion of the $\beta\beta0\nu$ process
vis-a-vis ongoing and forthcoming experiments. Finally, a thorough treatment is
given of baryogenesis via leptogenesis in this scenario, primarily with the
assumption that the lepton asymmetry produced by the decays of $N_1$ only
matters here with the asymmetry produced by $N_2$ being washed out. Tight upper
and lower bounds on the mass of $N_1$ are obtained from the constraint of
obtaining the correct observed range of the baryon asymmetry parameter and the
role played by $N_2$ is elucidated thereafter. The mildly hierarchical
right-chiral neutrino case (including the quasidegenerate possibility) is
discussed in an Appendix.Comment: 30 pages, 6 figures, 4 tables, version to appear in JHE
Holographic Four-Point Functions in the (2, 0) Theory

We revisit the calculation of holographic correlators for eleven-dimensional
supergravity on $AdS_7\times S^4$. Our methods rely entirely on symmetry and
eschew detailed knowledge of the supergravity effective action. By an extension
of the position space approach developed in [1, 2] for the $AdS_5\times S^5$
background, we compute four-point correlators of one-half BPS operators for
identical weights $k=2, 3, 4$. The $k=2$ case corresponds to the four-point
function of the stress-tensor multiplet, which was already known, while the
other two cases are new. We also translate the problem in Mellin space, where
the solution of the superconformal Ward identity takes a surprisingly simple
form. We formulate an algebraic problem, whose (conjecturally unique) solution
corresponds to the general one-half BPS four-point function.Comment: 33 pages; v2: typos corrected, to appear on JHE
LHC Search of New Higgs Boson via Resonant Di-Higgs Production with
  Decays into 4W

Searching for new Higgs particle beyond the observed light Higgs boson
h(125GeV) will unambiguously point to new physics beyond the standard model. We
study the resonant production of a CP-even heavy Higgs state $H^0$ in the
di-Higgs channel via, $gg\to H^0\to h^0h^0\to WW^*WW^*$, at the LHC Run-2 and
the high luminosity LHC (HL-LHC). We analyze two types of the $4W$ decay modes,
one with the same-sign di-leptons ($4W\to\ell^\pm\nu\ell^\pm\nu 4q$) and the
other with tri-leptons ($4W\to\ell^\pm\nu\ell^\mp\nu\ell^\pm\nu 2q$). We
perform a full simulation for the signals and backgrounds, and estimate the
discovery potential of the heavy Higgs state at the LHC Run-2 and the HL-LHC,
in the context of generical two-Higgs-doublet models (2HDM). We determine the
viable parameter space of the 2HDM as allowed by the theoretical constraints
and the current experimental limits. We systematically analyze the allowed
parameter space of the 2HDM which can be effectively probed by the heavy Higgs
searches of the LHC, and further compare this with the viable parameter region
under the current theoretical and experimental bounds.Comment: v3: JHEP published version, 34pp, 10 Figs(36 plots) and 9 Tables.
  Only minor typos fixed, references added. v2: JHEP version. All results and
  conclusions un-changed, discussions and references added. (This update is
  much delayed due to author's traveling and flu.
Notes on Melonic $O(N)^{q-1}$ Tensor Models

It has recently been demonstrated that the large N limit of a model of
fermions charged under the global/gauge symmetry group $O(N)^{q-1}$ agrees with
the large $N$ limit of the SYK model. In these notes we investigate aspects of
the dynamics of the $O(N)^{q-1}$ theories that differ from their SYK
counterparts. We argue that the spectrum of fluctuations about the finite
temperature saddle point in these theories has $(q-1)\frac{N^2}{2}$ new light
modes in addition to the light Schwarzian mode that exists even in the SYK
model, suggesting that the bulk dual description of theories differ
significantly if they both exist. We also study the thermal partition function
of a mass deformed version of the SYK model. At large mass we show that the
effective entropy of this theory grows with energy like $E \ln E$ (i.e. faster
than Hagedorn) up to energies of order $N^2$. The canonical partition function
of the model displays a deconfinement or Hawking Page type phase transition at
temperatures of order $1/\ln N$. We derive these results in the large mass
limit but argue that they are qualitatively robust to small corrections in
$J/m$.Comment: 60 pages, 7 figure
Pomeron fan diagrams in perturbative QCD

Within QCD reggeon field theory we study the formation of two subsequent
triple pomeron vertices in the process P$\to$PP$\to$PPP. We make use of an
earlier investigation ~\cite{Bartels:1999aw} of the six-reggeon amplitude in
deep inelastic scattering and show that in the large-$N_c$ limit pomeron fan
diagrams emerge with the same triple pomeron vertex in all places. We thus
confirm the BK-equation, but we also find additional terms related to the
reggeization of the gluon, and we discuss their potential significance. Our
analysis also includes the general pomeron $\to$ two odderon vertex: a
particular version of this vertex has been included into earlier
generalizations the BK equation.Comment: 22 pages, 10 figure
Holographic Floquet states II: Floquet condensation of vector mesons in
  nonequilibrium phase diagram

With the aim to reveal universal features of hadronic matter and correlated
Dirac insulators in strong AC-electric fields, we study the $\mathcal{N}=2$
supersymmetric QCD with a finite quark mass driven by a rotating electric field
$\mathcal{E}_x+i\mathcal{E}_y= E e^{i\Omega t}$. The analysis is done in the
holographically dual D3/D7 system in the co-rotating frame, effectively. The
nonequilibrium phase diagram is determined from the threshold electric field at
which the insulator phase breaks down to a conductive phase due to the AC
version of the Schwinger mechanism. The external field induces a rotating
current $\mathcal{J}_x + i \mathcal{J}_y = J e^{i\Omega t}$ originating from
vacuum polarization and dissipative current in the insulating and conductive
phases respectively. Intriguing features are observed as the frequency $\Omega$
approaches resonance with the meson excitation energy $\Omega_{\rm meson}$.
There, the threshold minimizes and a condensate of vector mesons with
oscillating current exists even in the zero driving field limit. This state,
which we call Floquet condensate of vector mesons, is expected to be
dynamically stable realizing a non-thermal fixed point that breaks time
translational and reversal symmetries. Our finding has many similarities with
exciton BEC discussed in solid state systems, where the semiconductor is to be
replaced by materials hosting gapped Dirac electrons, e.g. 3D topological
insulators or bismuth. Vector meson Floquet condensate may also have
implications in the pre-thermalized dynamics in heavy ion collision
experiments.Comment: 36 pages, 15 figure
Measurement of the inelastic pp cross-section at a centre-of-mass energy of 13 TeV

The cross-section for inelastic proton-proton collisions at a centre-of-mass energy of 13 TeV is measured with the LHCb detector. The fiducial cross-section for inelastic interactions producing at least one prompt long-lived charged particle with momentum p > 2 GeV/c in the pseudorapidity range 2 < η < 5 is determined to be σ[subscript acc] = 62.2 ± 0.2 ± 2.5 mb. The first uncertainty is the intrinsic systematic uncertainty of the measurement, the second is due to the uncertainty on the integrated luminosity. The statistical uncertainty is negligible. Extrapolation to full phase space yields the total inelastic proton-proton cross-section σ[subscript inel] = 75.4 ± 3.0 ± 4.5 mb, where the first uncertainty is experimental and the second due to the extrapolation. An updated value of the inelastic cross-section at a centre-of-mass energy of 7 TeV is also reported. Keywords: Global features Hadron-Hadron scattering (experiments) Minimum biasNational Science Foundation (U.S.
Quasi Single Field Inflation in the non-perturbative regime

In quasi single field inflation there are massive fields that interact with
the inflaton field. If these other fields are not much heavier than the Hubble
constant during inflation ($H$) these interactions can lead to important
consequences for the cosmological energy density perturbations. The simplest
model of this type has a real scalar inflaton field that interacts with another
real scalar $S$ (with mass $m$). In this model there is a mixing term of the
form $\mu {\dot \pi} S$, where $\pi$ is the Goldstone fluctuation that is
associated with the breaking of time translation invariance by the time
evolution of the inflaton field during the inflationary era. In this paper we
study this model in the region $(\mu/H )^2 +(m/H)^2 >9/4$ and $m/H \sim {\cal
O}(1)$ or less. For a large part of the parameter space in this region standard
perturbative methods are not applicable. Using numerical and analytic methods
we derive a number of new results. In addition we study how large $\mu/H$ has
to be for the large $\mu/H$ effective field theory approach to be applicable.Comment: 26 pages, 12 figure
Search for high-mass resonances in dilepton final states in proton-proton collisions at √s = 13 TeV

A search is presented for new high-mass resonances decaying into electron or muon pairs. The search uses proton-proton collision data at a centre-of-mass energy of 13 TeV collected by the CMS experiment at the LHC in 2016, corresponding to an integrated luminosity of 36 fb⁻¹. Observations are in agreement with standard model expectations. Upper limits on the product of a new resonance production cross section and branching fraction to dileptons are calculated in a model-independent manner. This permits the interpretation of the limits in models predicting a narrow dielectron or dimuon resonance. A scan of different intrinsic width hypotheses is performed. Limits are set on the masses of various hypothetical particles. For the Z′[subscript SSM](Z′[subscript ψ]) particle, which arises in the sequential standard model (superstring-inspired model), a lower mass limit of 4.50 (3.90) TeV is set at 95% confidence level. The lightest Kaluza-Klein graviton arising in the Randall-Sundrum model of extra dimensions, with coupling parameters k/MPl of 0.01, 0.05, and 0.10, is excluded at 95% confidence level below 2.10, 3.65, and 4.25 TeV, respectively. In a simplified model of dark matter production via a vector or axial vector mediator, limits at 95% confidence level are obtained on the masses of the dark matter particle and its mediator
Bulk Phase Shift, CFT Regge Limit and Einstein Gravity

The bulk phase shift, related to a CFT four-point function, describes
two-to-two scattering at fixed impact parameter in the dual AdS spacetime. We
describe its properties for a generic CFT and then focus on large $N$ CFTs with
classical bulk duals. We compute the bulk phase shift for vector operators
using Regge theory. We use causality and unitarity to put bounds on the bulk
phase shift. The resulting constraints bound three-point functions of two
vector operators and the stress tensor in terms of the gap of the theory.
Similar bounds should hold for any spinning operator in a CFT. Holographically
this implies that in a classical gravitational theory any non-minimal coupling
to the graviton, as well as any other particle with spin greater than or equal
to two, is suppressed by the mass of higher spin particles.Comment: 70 pages, 3 figure
Probing beyond ETH at large $c$

We study probe corrections to the Eigenstate Thermalization Hypothesis (ETH)
in the context of 2D CFTs with large central charge and a sparse spectrum of
low dimension operators. In particular, we focus on observables in the form of
non-local composite operators
$\mathcal{O}_{obs}(x)=\mathcal{O}_L(x)\mathcal{O}_L(0)$ with $h_L\ll c$. As a
light probe, $\mathcal{O}_{obs}(x)$ is constrained by ETH and satisfies
$\langle \mathcal{O}_{obs}(x)\rangle_{h_H}\approx \langle
\mathcal{O}_{obs}(x)\rangle_{\text{micro}}$ for a high energy energy eigenstate
$| h_H\rangle$. In the CFTs of interests, $\langle
\mathcal{O}_{obs}(x)\rangle_{h_H}$ is related to a Heavy-Heavy-Light-Light (HL)
correlator, and can be approximated by the vacuum Virasoro block, which we
focus on computing. A sharp consequence of ETH for $\mathcal{O}_{obs}(x)$ is
the so called "forbidden singularities", arising from the emergent thermal
periodicity in imaginary time. Using the monodromy method, we show that finite
probe corrections of the form $\mathcal{O}(h_L/c)$ drastically alter both sides
of the ETH equality, replacing each thermal singularity with a pair of
branch-cuts. Via the branch-cuts, the vacuum blocks are connected to infinitely
many additional "saddles". We discuss and verify how such violent modification
in analytic structure leads to a natural guess for the blocks at finite $c$: a
series of zeros that condense into branch cuts as $c\to\infty$. We also discuss
some interesting evidences connecting these to the Stoke's phenomena, which are
non-perturbative $e^{-c}$ effects. As a related aspect of these probe
modifications, we also compute the Renyi-entropy $S_n$ in high energy
eigenstates on a circle. For subsystems much larger than the thermal length, we
obtain a WKB solution to the monodromy problem, and deduce from this the
entanglement spectrum.Comment: 35 pages, 40 figures, additional results and comments adde
Naturalness and Dark Matter in a Realistic Intersecting D6-Brane Model

We revisit a three-family Pati-Salam model with a realistic phenomenology
from intersecting D6-branes in Type IIA string theory compactified on a
$\mathbf{T}^6/(\mathbb{Z}_2 \times \mathbb{Z}_2)$ orientifold, and study its
naturalness in view of the current LHC and dark matter searches. We discuss
spectrum and phenomenological features of this scenario demanding fine tuning
better than 1\%. This requirement restricts the lightest neutralino to have
mass less than about 600 GeV. We observe that the viable parameter space is
tightly constrained by the requirements of naturalness and consistency with the
observed dark matter relic density, so that it is fully testable at current and
future dark matter searches, unless a non-thermal production mechanism of dark
matter is at work. We find that $Z$-resonance, $h$-resonance, $A$-funnel and
light stau/stop-neutralino coannihilation solutions are consistent with current
LHC and dark matter constraints while the "well-tempered" neutralino scenario
is ruled out in our model. Moreover, we observe that only Bino, Higgsinos,
right-handed staus and stops can have mass below 1 TeV.Comment: 20 pages, 4 figures, 1 tabl