pinecone/core-2020-05-10-deduplication huggingface dataset:
Lorentz Violation in Warped Extra Dimensions

Higher dimensional theories which address some of the problematic issues of
the Standard Model(SM) naturally involve some form of $D=4+n$-dimensional
Lorentz invariance violation (LIV). In such models the fundamental physics
which leads to, e.g., field localization, orbifolding, the existence of brane
terms and the compactification process all can introduce LIV in the higher
dimensional theory while still preserving 4-d Lorentz invariance. In this
paper, attempting to capture some of this physics, we extend our previous
analysis of LIV in 5-d UED-type models to those with 5-d warped extra
dimensions. To be specific, we employ the 5-d analog of the SM Extension of
Kostelecky et. al. ~which incorporates a complete set of operators arising from
spontaneous LIV. We show that while the response of the bulk scalar, fermion
and gauge fields to the addition of LIV operators in warped models is
qualitatively similar to what happens in the flat 5-d UED case, the gravity
sector of these models reacts very differently than in flat space.
Specifically, we show that LIV in this warped case leads to a non-zero bulk
mass for the 5-d graviton and so the would-be zero mode, which we identify as
the usual 4-d graviton, must necessarily become massive. The origin of this
mass term is the simultaneous existence of the constant non-zero $AdS_5$
curvature and the loss of general co-ordinate invariance via LIV in the 5-d
theory. Thus warped 5-d models with LIV in the gravity sector are not
phenomenologically viable.Comment: 14 pages, 4 figs; discussion added, algebra repaire
On theories of enhanced CP violation in B_s,d meson mixing

The DO collaboration has measured a deviation from the standard model (SM)
prediction in the like sign dimuon asymmetry in semileptonic b decay with a
significance of 3.2 sigma. We discuss how minimal flavour violating (MFV)
models with multiple scalar representations can lead to this deviation through
tree level exchanges of new MFV scalars. We review how the two scalar doublet
model can accommodate this result and discuss some of its phenomenology. Limits
on electric dipole moments suggest that in this model the coupling of the
charged scalar to the right handed u-type quarks is suppressed while its
coupling to the d-type right handed quarks must be enhanced. We construct an
extension of the MFV two scalar doublet model where this occurs naturally.Comment: 10 pages, 7 figures, v3 final JHEP versio
Bounds and Decays of New Heavy Vector-like Top Partners

We study the phenomenology of new heavy vector-like fermions that couple to
the third generation quarks via Yukawa interactions, covering all the allowed
representations under the standard model gauge groups. We first review tree and
loop level bounds on these states. We then discuss tree level decays and
loop-induced decays to photon or gluon plus top. The main decays at tree level
are to W b and/or Z and Higgs plus top via the new Yukawa couplings. The
radiative loop decays turn out to be quite close to the naive estimate: in all
cases, in the allowed perturbative parameter space, the branching ratios are
mildly sensitive on the new Yukawa couplings and small. We therefore conclude
that the new states can be observed at the LHC and that the tree level decays
can allow to distinguish the different representations. Moreover, the
observation of the radiative decays at the LHC would suggest a large Yukawa
coupling in the non-perturbative regime.Comment: 32 pages, 2 tables, 10 figure
Gauge-Higgs unification in spontaneously created fuzzy extra dimensions

We propose gauge-Higgs unification in fuzzy extra dimensions as a possible solution to the Higgs naturalness problem. In our approach, the fuzzy extra dimensions are created spontaneously as a vacuum solution of certain four-dimensional gauge theory. As an example, we construct a model which has a fuzzy torus as its vacuum. The Higgs field in our model is associated with the Wilson loop wrapped on the fuzzy torus. We show that the quadratic divergence in the mass of the Higgs field in the one-loop effective potential is absent. We then argue based on symmetries that the quantum corrections to the Higgs mass is suppressed including all loop contributions. We also consider a realization on the worldvolume theory of D3-branes probing C-3/(Z(N) x Z(N)) orbifold with discrete torsion
Lifshitz black holes in Brans-Dicke theory

We present an exact asymptotically Lifshitz black hole solution in
Brans-Dicke theory of gravity in arbitrary $n(\ge 3)$ dimensions in presence of
a power-law potential. In this solution, the dynamical exponent $z$ is
determined in terms of the Brans-Dicke parameter $\omega$ and $n$. Asymptotic
Lifshitz condition at infinity requires $z>1$, which corresponds to
$-(n-1)/(n-2) \le \omega < -n/(n-1)$. On the other hand, the no-ghost condition
for the scalar field in the Einstein frame requires $0<z \le 2(n-2)/(n-3)$. We
compute the Hawking temperature of the black hole solution and discuss the
problems encountered and the proposals in defining its thermodynamic
properties. A generalized solution charged under the Maxwell field is also
presented.Comment: 32 pages, no figure. v2: revised version. Section 3.1 and Appendix B
  improved. The argument in Appendix A clarified. v3: References added. v4:
  analysis on the black hole thermodynamical properties corrected. Final
  version to appear in JHE
Splitting strings on integrable backgrounds

Open Access at SpringerUsing integrability we reduce the problem of constructing general classical splitting string solutions on R??S3 to a series of Birkhoff factorization problems. Namely, given any incoming string solution satisfying a necessary self-intersection property at some given instant in time, we use the integrability of the worldsheet ??-model to implicitly construct the pair of outgoing strings resulting from a split. The solution for each outgoing string is expressed recursively through a sequence of dressing transformations with parameters determined by the solutions to Birkhoff factorization problems in an appropriate real form of the loop group of SL2(C)
Higgsstrahlung from R-hadrons

If R hadrons are discovered at the LHC, investigation of their properties
will be of paramount importance. One important question is how much of the
R-hadron mass is due to electroweak symmetry breaking, i.e. the coupling of the
Higgs to R-hadrons. In this paper we show that in models where the Higgs has a
sizable coupling to R-hadrons we can readily observe Higgs production in
association with a pair of R-hadrons ("Higgsstrahlung"). This process can be
used to distinguish between different models of R-hadrons. It may be the
discovery mode of the Higgs for low mass Higgs bosons, and provides a
low-background Higgs sample to study h to bb.Comment: 9 pages, 3 figures, 2 table
Supersymmetric Boundaries and Junctions in Four Dimensions

We make a comprehensive study of (rigid) N=1 supersymmetric sigma-models with
general K\"ahler potentials K and superpotentials w on four-dimensional
space-times with boundaries. We determine the minimal (non-supersymmetric)
boundary terms one must add to the standard bulk action to make it off-shell
invariant under half the supersymmetries without imposing any boundary
conditions. Susy boundary conditions do arise from the variational principle
when studying the dynamics. Upon including an additional boundary action that
depends on an arbitrary real boundary potential B one can generate very general
susy boundary conditions. We show that for any set of susy boundary conditions
that define a Lagrangian submanifold of the K\"ahler manifold, an appropriate
boundary potential B can be found. Thus the non-linear sigma-model on a
manifold with boundary is characterised by the tripel (K,B,w). We also discuss
the susy coupling to new boundary superfields and generalize our results to
supersymmetric junctions between completely different susy sigma-models, living
on adjacent domains and interacting through a "permeable" wall. We obtain the
supersymmetric matching conditions that allow us to couple models with
different K\"ahler potentials and superpotentials on each side of the wall.Comment: 38 pages, 1 figur
Physical Theories, Eternal Inflation, and Quantum Universe

We present a framework in which well-defined predictions are obtained in an
eternally inflating multiverse, based on the principles of quantum mechanics.
We show that the entire multiverse is described purely from the viewpoint of a
single "observer," who describes the world as a quantum state defined on
his/her past light cones bounded by the (stretched) apparent horizons. We find
that quantum mechanics plays an essential role in regulating infinities. The
framework is "gauge invariant," i.e. predictions do not depend on how spacetime
is parametrized, as it should be in a theory of quantum gravity. Our framework
provides a fully unified treatment of quantum measurement processes and the
multiverse. We conclude that the eternally inflating multiverse and many worlds
in quantum mechanics are the same. Other important implications include: global
spacetime can be viewed as a derived concept; the multiverse is a transient
phenomenon during the world relaxing into a supersymmetric Minkowski state. We
also present a theory of "initial conditions" for the multiverse. By
extrapolating our framework to the extreme, we arrive at a picture that the
entire multiverse is a fluctuation in the stationary, fractal
"mega-multiverse," in which an infinite sequence of multiverse productions
occurs. The framework discussed here does not suffer from problems/paradoxes
plaguing other measures proposed earlier, such as the youngness paradox, the
Boltzmann brain problem, and a peculiar "end" of time.Comment: 66 pages, 13 figures, longer version of the abstract in the body of
  the paper; v2: minor revisio
Transverse-momentum resummation: Higgs boson production at the Tevatron and the LHC

We consider the transverse-momentum (qT ) distribution of Standard Model Higgs bosons produced by gluon fusion in hadron collisions. At small qT (qT ≪ mH , mH being the mass of the Higgs boson), we resum the logarithmically-enhanced contributions due to multiple soft-gluon emission to all order in QCD perturbation theory. At interme-diate and large values of qT (qT < mH), we consistently combine resummation with the known fixed-order results. We use the most advanced perturbative information that is available at present: next-to-next-to-leading logarithmic resummation combined with the next-to-leading fixed-order calculation. We extend previous results including exactly all the perturbative terms up to order αS in our computation and, after integration over qT, we recover the known next-to-next-to-leading order result for the total cross section. We present numerical results at the Tevatron and the LHC, together with an estimate of the corresponding uncertainties. Our calculation is implemented in an updated version of the numerical code HqT
The MSSM confronts the precision electroweak data and the muon g-2

We update the electroweak study of the predictions of the Minimal
Supersymmetric Standard Model (MSSM) including the recent results on the muon
anomalous magnetic moment, the weak boson masses, and the final precision data
on the Z boson parameters from LEP and SLC. We find that the region of the
parameter space where the slepton masses are a few hundred GeV is favored from
the muon g-2 for \tan\beta \ltsim 10, whereas for \tan\beta \simeq 50 heavier
slepton mass up to \sim 1000 GeV can account for the reported 3.2 \sigma
difference between its experimental value and the Standard Model (SM)
prediction. As for the electroweak measurements, the SM gives a good
description, and the sfermions lighter than 200 GeV tend to make the fit worse.
We find, however, that sleptons as light as 100 to 200 GeV are favored also
from the electroweak data, if we leave out the jet asymmetry data that do not
agree with the leptonic asymmetry data. We extend the survey of the preferred
MSSM parameters by including the constraints from the b \to s \gamma
transition, and find favorable scenarios in the minimal supergravity, gauge-,
and mirage-mediation models of supersymmetry breaking.Comment: 40 pages, 12 figures. v2: minor changes, references added, version to
  appear in JHE
Classicalization of Gravitons and Goldstones

We establish a close parallel between classicalization of gravitons and
derivatively-coupled Nambu-Goldstone-type scalars. We show, that black hole
formation in high energy scattering process represents classicalization with
the classicalization radius given by Schwarzschild radius of center of mass
energy, and with the precursor of black hole entropy being given by number of
soft quanta composing this classical configuration. Such an entropy-equivalent
is defined for scalar classicalons also and is responsible for exponential
suppression of their decay into small number of final particles. This parallel
works in both ways. For optimists that are willing to hypothesize that gravity
may indeed self-unitarize at high energies via black hole formation, it
illustrates that the Goldstones may not be much different in this respect, and
they classicalize essentially by similar dynamics as gravitons. In the other
direction, it may serve as an useful de-mystifier of
via-black-hole-unitarization process and of the role of entropy in it, as it
illustrates, that much more prosaic scalar theories essentially do the same.
Finally, it illustrates that in both cases classicalization is the defining
property for unitarization, and that it sets-in before one can talk about
accompanying properties, such as entropy and thermality of static classicalons
(black holes). These properties are by-products of classicalization, and their
equivalents can be defined for non-gravitational cases of classicalization.Comment: 23 page
Z' Bosons at Colliders: a Bayesian Viewpoint

We revisit the CDF data on di-muon production to impose constraints on a
large class of Z' bosons occurring in a variety of E_6 GUT based models. We
analyze the dependence of these limits on various factors contributing to the
production cross-section, showing that currently systematic and theoretical
uncertainties play a relatively minor role. Driven by this observation, we
emphasize the use of the Bayesian statistical method, which allows us to
straightforwardly (i) vary the gauge coupling strength, g', of the underlying
U(1)'; (ii) include interference effects with the Z' amplitude (which are
especially important for large g'); (iii) smoothly vary the U(1)' charges; (iv)
combine these data with the electroweak precision constraints as well as with
other observables obtained from colliders such as LEP 2 and the LHC; and (v)
find preferred regions in parameter space once an excess is seen. We adopt this
method as a complementary approach for a couple of sample models and find
limits on the Z' mass, generally differing by only a few percent from the
corresponding CDF ones when we follow their approach. Another general result is
that the interference effects are quite relevant if one aims at discriminating
between models. Finally, the Bayesian approach frees us of any ad hoc
assumptions about the number of events needed to constitute a signal or
exclusion limit for various actual and hypothetical reference energies and
luminosities at the Tevatron and the LHC.Comment: PDFLaTeX, 24 pages, 7 figures. Version with improved tables and
  figure
Classical integrability of Schrödinger sigma models and q-deformed Poincaré symmetry

We discuss classical integrable structure of two-dimensional sigma models which have three-dimensional Schrödinger spacetimes as target spaces. The Schrödinger spacetimes are regarded as null-like deformations of AdS3. The original AdS3 isometry SL(2, R)L × SL(2, R)R is broken to SL(2, R)L × U(1)R due to the deformation. According to this symmetry, there are two descriptions to describe the classical dynamics of the system, 1) the SL(2, R)L description and 2) the enhanced U(1)R description. In the former 1), we show that the Yangian symmetry is realized by improving the SL(2, R)L Noether current. Then a Lax pair is constructed with the improved current and the classical inte-grability is shown by deriving the r/s-matrix algebra. In the latter 2), we find a non-local current by using a scaling limit of warped AdS3 and that it enhances U(1)R to a q-deformed Poincaré algebra. Then another Lax pair is presented and the corresponding r/s-matrices are also computed. The two descriptions are equivalent via a non-local map
A natural language for AdS/CFT correlators.

We provide dramatic evidence that ‘Mellin space’ is the natural home for correlation functions in CFTs with weakly coupled bulk duals. In Mellin space, CFT correlators have poles corresponding to an OPE decomposition into ‘left’ and ‘right’ sub-correlators, in direct analogy with the factorization channels of scattering amplitudes. In the regime where these correlators can be computed by tree level Witten diagrams in AdS, we derive an explicit formula for the residues of Mellin amplitudes at the corresponding factorization poles, and we use the conformal Casimir to show that these amplitudes obey algebraic finite difference equations. By analyzing the recursive structure of our factorization formula we obtain simple diagrammatic rules for the construction of Mellin amplitudes corresponding to tree-level Witten diagrams in any bulk scalar theory. We prove the diagrammatic rules using our finite difference equations. Finally, we show that our factorization formula and our diagrammatic rules morph into the flat space S-Matrix of the bulk theory, reproducing the usual Feynman rules, when we take the flat space limit of AdS/CFT. Throughout we emphasize a deep analogy with the properties of flat space scattering amplitudes in momentum space, which suggests that the Mellin amplitude may provide a holographic definition of the flat space S-Matrix
Holographic Symmetry-Breaking Phases in AdS$_3$/CFT$_2$

In this note we study the symmetry-breaking phases of 3D gravity coupled to
matter. In particular, we consider black holes with scalar hair as a model of
symmetry-breaking phases of a strongly coupled 1+1 dimensional CFT. In the case
of a discrete symmetry, we show that these theories admit metastable phases of
broken symmetry and study the thermodynamics of these phases. We also
demonstrate that the 3D Einstein-Maxwell theory shows continuous symmetry
breaking at low temperature. The apparent contradiction with the
Coleman-Mermin-Wagner theorem is discussed.Comment: 15 pages, 7 figur
Relevant Deformations in Open String Field Theory: a Simple Solution for
  Lumps

We propose a remarkably simple solution of cubic open string field theory
which describes inhomogeneous tachyon condensation. The solution is in
one-to-one correspondence with the IR fixed point of the RG-flow generated in
the two--dimensional world-sheet theory by integrating a relevant operator with
mild enough OPE on the boundary. It is shown how the closed string overlap
correctly captures the shift in the closed string one point function between
the UV and the IR limits of the flow. Examples of lumps in non-compact and
compact transverse directions are given.Comment: 45 pages. v2: typos and minor improvements. v3: submitted to jhe
't Hooft Operators in Gauge Theory from Toda CFT

We construct loop operators in two dimensional Toda CFT and calculate with
them the exact expectation value of certain supersymmetric 't Hooft and dyonic
loop operators in four dimensional \Ncal=2 gauge theories with SU(N) gauge
group. Explicit formulae for 't Hooft and dyonic operators in \Ncal=2^* and
\Ncal=2 conformal SQCD with SU(N) gauge group are presented. We also briefly
speculate on the Toda CFT realization of arbitrary loop operators in these
gauge theories in terms of topological web operators in Toda CFT.Comment: 49 pages, LaTeX. Typos fixed, references adde
Casimir Energy for a Coupled Fermion-Soliton System

In this paper we compute the Casimir energy for a coupled
fermion-pseudoscalar field system. In the model considered in this paper the
pseudoscalar field is \textit{static} and \textit{prescribed} with two
adjustable parameters. These parameters determine the values of the field at
infinity ($\pm \theta_0$) and its scale of variation ($\mu$). One can build up
a field configuration with arbitrary topological charge by changing $\theta_0$,
and interpolate between the extreme adiabatic and non-adiabatic regimes by
changing $\mu$. This system is exactly solvable and therefore we compute the
Casimir energy exactly and unambiguously by using an energy density subtraction
scheme. We show that in general the Casimir energy goes to zero in the extreme
adiabatic limit, and in the extreme non-adiabatic limit when the asymptotic
values of the pseudoscalar field properly correspond to a configuration with an
arbitrary topological charge. Moreover, in general the Casimir energy is always
positive and on the average an increasing function of $\theta_0$ and always has
local maxima when there is a zero mode, showing that these configurations are
energetically unfavorable. We also compute and display the energy densities
associated with the spectral deficiencies in both of the continua, and those of
the bound states. We show that the energy densities associated with the
distortion of the spectrum of the states with $E>0$ and $E<0$ are mirror images
of each other. We also compute and display the Casimir energy density. Finally
we compute the energy of a system consisting of a soliton and a valance
electron and show that the Casimir energy of the system is comparable with the
binding energy.Comment: 11 pages, 6 figure
Nonperturbative aspects of ABJM theory

Using the matrix model which calculates the exact free energy of ABJM theory
on S^3 we study non-perturbative effects in the large N expansion of this
model, i.e., in the genus expansion of type IIA string theory on AdS4xCP^3. We
propose a general prescription to extract spacetime instanton actions from
general matrix models, in terms of period integrals of the spectral curve, and
we use it to determine them explicitly in the ABJM matrix model, as exact
functions of the 't Hooft coupling. We confirm numerically that these
instantons control the asymptotic growth of the genus expansion. Furthermore,
we find that the dominant instanton action at strong coupling determined in
this way exactly matches the action of an Euclidean D2-brane instanton wrapping
RP^3.Comment: 26 pages, 14 figures. v2: small corrections, final version published
  in JHE
Localization of N=4 Superconformal Field Theory on S^1 x S^3 and Index

We provide the geometrical meaning of the ${\cal N}=4$ superconformal index.
With this interpretation, the ${\cal N}=4$ superconformal index can be realized
as the partition function on a Scherk-Schwarz deformed background. We apply the
localization method in TQFT to compute the deformed partition function since
the deformed action can be written as a $\delta_\epsilon$-exact form. The
critical points of the deformed action turn out to be the space of flat
connections which are, in fact, zero modes of the gauge field. The one-loop
evaluation over the space of flat connections reduces to the matrix integral by
which the ${\cal N}=4$ superconformal index is expressed.Comment: 42+1 pages, 2 figures, JHEP style: v1.2.3 minor corrections, v4 major
  revision, conclusions essentially unchanged, v5 published versio