pinecone/core-2020-05-10-deduplication huggingface dataset:
6D supergravity without tensor multiplets

We systematically investigate the finite set of possible gauge groups and
matter content for N = 1 supergravity theories in six dimensions with no tensor
multiplets, focusing on nonabelian gauge groups which are a product of SU(N)
factors. We identify a number of models which obey all known low-energy
consistency conditions, but which have no known string theory realization. Many
of these models contain novel matter representations, suggesting possible new
string theory constructions. Many of the most exotic matter structures arise in
models which precisely saturate the gravitational anomaly bound on the number
of hypermultiplets. Such models have a rigid symmetry structure, in the sense
that there are no moduli which leave the full gauge group unbroken.Comment: 31 pages, latex; v2, v3: minor corrections, references adde
New differential equations for on-shell loop integrals

We present a novel type of differential equations for on-shell loop
integrals. The equations are second-order and importantly, they reduce the loop
level by one, so that they can be solved iteratively in the loop order. We
present several infinite series of integrals satisfying such iterative
differential equations. The differential operators we use are best written
using momentum twistor space. The use of the latter was advocated in recent
papers discussing loop integrals in N=4 super Yang-Mills. One of our
motivations is to provide a tool for deriving analytical results for scattering
amplitudes in this theory. We show that the integrals needed for planar MHV
amplitudes up to two loops can be thought of as deriving from a single master
topology. The master integral satisfies our differential equations, and so do
most of the reduced integrals. A consequence of the differential equations is
that the integrals we discuss are not arbitrarily complicated transcendental
functions. For two specific two-loop integrals we give the full analytic
solution. The simplicity of the integrals appearing in the scattering
amplitudes in planar N=4 super Yang-Mills is strongly suggestive of a relation
to the conjectured underlying integrability of the theory. We expect these
differential equations to be relevant for all planar MHV and non-MHV
amplitudes. We also discuss possible extensions of our method to more general
classes of integrals.Comment: 39 pages, 8 figures; v2: typos corrected, definition of harmonic
  polylogarithms adde
Forward-backward asymmetry in top quark production from light colored
  scalars in SO(10) model

The forward-backward asymmetry in top pair production at Tevatron has been
reconfirmed by the CDF collaboration with 5.3 fb^{-1} of accumulated data.
These measurements also report that the asymmetry is the largest in regions of
high invariant mass M_{t\bar{t}} and rapidity difference |\Delta Y|. We
consider light colored sextet scalars appearing in a particular
non-supersymmetric \10 grand unification model within the \bar{126} scalar
representation. These scalar states have masses in the range of 300
\text{GeV}-2 \text{TeV} consistent with the requirements of gauge coupling
unification and bounds on the proton lifetime. The cross section and the total
asymmetry can be simultaneously explained with the contributions of these
scalars within 1$\sigma$. We find that the simultaneous fitting of the cross
section, the total asymmetry and the asymmetries in different rapidity and
M_{t\bar{t}} bins gives only a marginal improvement over the SM contribution.
We also study various production mechanisms of these colored sextet scalars at
the LHC.Comment: 22 pages, 11 Figures, References added, Section III and V modified.
  Version accepted for publication in JHE
An Operator Product Expansion for Polygonal null Wilson Loops

We consider polygonal Wilson loops with null edges in conformal gauge
theories. We derive an OPE-like expansion when several successive lines of the
polygon are becoming aligned. The limit corresponds to a collinear, or
multicollinear, limit and we explain the systematics of all the subleading
corrections, going beyond the leading terms that were previously considered.
These subleading corrections are governed by excitations of high spin
operators, or excitations of a flux tube that goes between two Wilson lines.
The discussion is valid for any conformal gauge theory, for any coupling and in
any dimension. For N=4 super Yang Mills we check this expansion at strong
coupling and at two loops at weak coupling . We also make predictions for the
remainder function at higher loops. In the process, we also derived a new
version for the TBA integral equations that determine the strong coupling
answer and present the area as the associated Yang-Yang functional.Comment: 48 pages, 12 figures, harvmac. v2 fixed a small issue regarding
  divergence
CP violation in charged Higgs production and decays in the Complex Two
  Higgs Doublet Model

We study the effects of CP violation in charged Higgs boson production $pp\to
t H^\pm + X$ at the LHC, as well as in the charged Higgs boson decays $H^\pm
\to t b$ and $H^\pm \to W^\pm H_i^0$, $i=1,2,3$. The study is done in the
framework of the type II complex Two Higgs Doublet Model (2HDM) with softly
broken $Z_2$ symmetry. In this model violation of CP invariance is induced by
the complex parameter $m^2_{12}$ of the tree-level Higgs potential. We
calculate the CP violating rate asymmetries for $H^+$ and $H^-$ production and
decays as well as for the combined processes at one-loop level and perform a
detailed numerical analysis. All calculations are done with the automatic
amplitude generator FeynArts and the calculational tool FormCalc, for which we
have written a complete complex 2HDM model file and relevant fortran drivers.
The implementation of the complex 2HDM in FeynArts and FormCalc is described.
In comparison with the analogous results in the MSSM, all considered CP
violating asymmetries are smaller by an order of magnitude and do not exceed 2
to 3%.Comment: 35 pages, 17 figures, version published in JHE
The partition bundle of type A_{N-1} (2, 0) theory

Six-dimensional (2, 0) theory can be defined on a large class of
six-manifolds endowed with some additional topological and geometric data (i.e.
an orientation, a spin structure, a conformal structure, and an R-symmetry
bundle with connection). We discuss the nature of the object that generalizes
the partition function of a more conventional quantum theory. This object takes
its values in a certain complex vector space, which fits together into the
total space of a complex vector bundle (the `partition bundle') as the data on
the six-manifold is varied in its infinite-dimensional parameter space. In this
context, an important role is played by the middle-dimensional intermediate
Jacobian of the six-manifold endowed with some additional data (i.e. a
symplectic structure, a quadratic form, and a complex structure). We define a
certain hermitian vector bundle over this finite-dimensional parameter space.
The partition bundle is then given by the pullback of the latter bundle by the
map from the parameter space related to the six-manifold to the parameter space
related to the intermediate Jacobian.Comment: 15 pages. Minor changes, added reference
Higgs Production with a Central Jet Veto at NNLL+NNLO

A major ingredient in Higgs searches at the Tevatron and LHC is the
elimination of backgrounds with jets. In current H -> WW -> lnulnu searches,
jet algorithms are used to veto central jets to obtain a 0-jet sample, which is
then analyzed to discover the Higgs signal. Imposing this tight jet veto
induces large double logarithms which significantly modify the Higgs production
cross section. These jet-veto logarithms are presently only accounted for at
fixed order or with the leading-logarithmic summation from parton-shower Monte
Carlos. Here we consider Higgs production with an inclusive event-shape
variable for the jet veto, namely beam thrust Tau_cm, which has a close
correspondence with a traditional p_T jet veto. Tau_cm allows us to
systematically sum the large jet-veto logarithms to higher orders and to
provide better estimates for theoretical uncertainties. We present results for
the 0-jet Higgs production cross section from gluon fusion at
next-to-next-to-leading-logarithmic order (NNLL), fully incorporating
fixed-order results at next-to-next-to-leading order (NNLO). At this order the
scale uncertainty is 15-20%, depending on the cut, implying that a larger scale
uncertainty should be used in current Tevatron bounds on the Higgs.Comment: 38 pages + appendices, 21 figures, v2: extended discussion section,
  added figure with individual scale variations, journal versio
Gauged Flavor Group with Left-Right Symmetry

We construct an anomaly-free extension of the left-right symmetric model,
where the maximal flavor group is gauged and anomaly cancellation is guaranteed
by adding new vectorlike fermion states. We address the question of the lowest
allowed flavor symmetry scale consistent with data. Because of the mechanism
recently pointed out by Grinstein et al. tree-level flavor changing neutral
currents turn out to play a very weak constraining role. The same occurs, in
our model, for electroweak precision observables. The main constraint turns out
to come from WR-mediated flavor changing neutral current box diagrams,
primarily K - Kbar mixing. In the case where discrete parity symmetry is
present at the TeV scale, this constraint implies lower bounds on the mass of
vectorlike fermions and flavor bosons of 5 and 10 TeV respectively. However,
these limits are weakened under the condition that only SU(2)_R x U(1)_{B-L} is
restored at the TeV scale, but not parity. For example, assuming the SU(2)
gauge couplings in the ratio gR/gL approx 0.7 allows the above limits to go
down by half for both vectorlike fermions and flavor bosons. Our model provides
a framework for accommodating neutrino masses and, in the parity symmetric
case, provides a solution to the strong CP problem. The bound on the lepton
flavor gauging scale is somewhat stronger, because of Big Bang Nucleosynthesis
constraints. We argue, however, that the applicability of these constraints
depends on the mechanism at work for the generation of neutrino masses.Comment: 1+23 pages, 1 table, 5 figures. v3: some more textual fixes (main
  change: discussion of Lepton Flavor Violating observables rephrased). Matches
  journal versio
The phases of deuterium at extreme densities

We consider deuterium compressed to higher than atomic, but lower than
nuclear densities. At such densities deuterium is a superconducting quantum
liquid. Generically, two superconducting phases compete, a "ferromagnetic" and
a "nematic" one. We provide a power counting argument suggesting that the
dominant interactions in the deuteron liquid are perturbative (but screened)
Coulomb interactions. At very high densities the ground state is determined by
very small nuclear interaction effects that probably favor the ferromagnetic
phase. At lower densities the symmetry of the theory is effectively enhanced to
SU(3), and the quantum liquid enters a novel phase, neither ferromagnetic nor
nematic. Our results can serve as a starting point for investigations of the
phase dynamics of deuteron liquids, as well as exploration of the stability and
dynamics of the rich variety of topological objects that may occur in phases of
the deuteron quantum liquid, which range from Alice strings to spin skyrmions
to Z_2 vortices.Comment: 9 pages, 6 figures; v2: fixed typo
Light Stop Decay in the MSSM with Minimal Flavour Violation

In supersymmetric scenarios with a light stop particle $\tilde{t}_1$ and a
small mass difference to the lightest supersymmetric particle (LSP) assumed to
be the lightest neutralino, the flavour changing neutral current decay
$\tilde{t}_1 \to c \tilde{\chi}_1^0$ can be the dominant decay channel and can
exceed the four-body stop decay for certain parameter values. In the framework
of Minimal Flavour Violation (MFV) this decay is CKM-suppressed, thus inducing
long stop lifetimes. Stop decay length measurements at the LHC can then be
exploited to test models with minimal flavour breaking through Standard Model
Yukawa couplings. The decay width has been given some time ago by an
approximate formula, which takes into account the leading logarithms of the MFV
scale. In this paper we calculate the exact one-loop decay width in the
framework of MFV. The comparison with the approximate result exhibits
deviations of the order of 10% for large MFV scales due to the neglected
non-logarithmic terms in the approximate decay formula. The difference in the
branching ratios is negligible. The large logarithms have to be resummed. The
resummation is performed by the solution of the renormalization group
equations. The comparison of the exact one-loop result and the tree level
flavour changing neutral current decay, which incorporates the resummed
logarithms, demonstrates that the resummation effects are important and should
be taken into account.Comment: 29 page
Gravitational collapse of k-essence

We perform numerical simulations of the gravitational collapse of a k-essence
scalar field. When the field is sufficiently strongly gravitating, a black hole
forms. However, the black hole has two horizons: a light horizon (the ordinary
black hole horizon) and a sound horizon that traps k-essence. In certain cases
the k-essence signals can travel faster than light and the sound horizon is
inside the light horizon. Under those circumstances, k-essence signals can
escape from the black hole. Eventually, the two horizons merge and the
k-essence signals can no longer escape.Comment: 14 pages, 8 figure
A new approach to anti-neutrino running in long baseline neutrino
  oscillation experiments

We study the possibility to replace the anti-neutrino run of a long baseline
neutrino oscillation experiment, with anti-neutrinos from muon decay at rest.
The low energy of these neutrinos allows the use of inverse beta decay for
detection in a Gadolinium-doped water Cerenkov detector. We show that this
approach yields a factor of five times larger anti-neutrino event sample. The
resulting discovery reaches in theta_13, the mass hierarchy and leptonic CP
violation are compared with those from a conventional superbeam experiment with
combined neutrino and anti-neutrino running. We find that this approach yields
a greatly improved reach for CP violation and theta_13 while leaving the
ability to measure the mass hierarchy intact.Comment: 4 pages, 2 pages, 1 tabl
g-functions and gluon scattering amplitudes at strong coupling

We study gluon scattering amplitudes/Wilson loops in =4 super Yang-Mills theory at strong coupling by calculating the area of the minimal surfaces in AdS 3 based on the associated thermodynamic Bethe ansatz system. The remainder function of the amplitudes is computed by evaluating the free energy, the T- and Y-functions of the homogeneous sine-Gordon model. Using conformal field theory (CFT) perturbation, we examine the mass corrections to the free energy around the CFT point corresponding to the regular polygonal Wilson loop. Based on the relation between the T-functions and the g-functions, which measure the boundary entropy, we calculate corrections to the T-and Y-functions as well as express them at the CFT point by the modular S-matrix. We evaluate the remainder function around the CFT point for 8 and 10-point amplitudes explicitly and compare these analytic expressions with the 2-loop formulas. The two rescaled remainder functions show very similar power series structures
The quantum mechanics of perfect fluids

We consider the canonical quantization of an ordinary fluid. The resulting
long-distance effective field theory is derivatively coupled, and therefore
strongly coupled in the UV. The system however exhibits a number of
peculiarities, associated with the vortex degrees of freedom. On the one hand,
these have formally a vanishing strong-coupling energy scale, thus suggesting
that the effective theory's regime of validity is vanishingly narrow. On the
other hand, we prove an analog of Coleman's theorem, whereby the semiclassical
vacuum has no quantum counterpart, thus suggesting that the vortex premature
strong-coupling phenomenon stems from a bad identification of the ground state
and of the perturbative degrees of freedom. Finally, vortices break the usual
connection between short distances and high energies, thus potentially
impairing the unitarity of the effective theory.Comment: 35 page
On factorizations in perturbative quantum gravity

Some features of Einstein gravity are most easily understood from string
theory but are not manifest at the level of the usual Lagrangian formulation.
One example is the factorization of gravity amplitudes into gauge theory
amplitudes. Based on the recently constructed `double field theory' and a
geometrical frame-like formalism developed by Siegel, we provide a framework of
perturbative Einstein gravity coupled to a 2-form and a dilaton in which, as a
consequence of T-duality, the Feynman rules factorize to all orders in
perturbation theory. We thereby establish the precise relation between the
field variables in different formulations and discuss the Lagrangian that, when
written in terms of these variables, makes a left-right factorization manifest.Comment: 18 pages, v2: reference added, to appear in JHE
Exotic Universal Solutions in Cubic Superstring Field Theory

We present a class of analytic solutions of cubic superstring field theory in
the universal sector on a non-BPS D-brane. Computation of the action and gauge
invariant overlap reveal that the solutions carry half the tension of a non-BPS
D-brane. However, the solutions do not satisfy the reality condition. In fact,
they display an intriguing topological structure: We find evidence that
conjugation of the solutions is equivalent to a gauge transformation that
cannot be continuously deformed to the identity.Comment: 53 pages, 6 figures. Added appendix on splitting charges and midpoint
  insertions. Improved presentation of the topological structure of the
  solutions. Version accepted at JHE
A Supersymmetric One Higgs Doublet Model

We present a supersymmetric extension of the Standard Model in which only one
electroweak doublet acquires a vacuum expectation value and gives mass to
Standard Model fermions. As well as the novel accommodation of a Standard Model
Higgs within a supersymmetric framework, this leads to a very predictive model,
with some advantages over the MSSM. In particular, problems with proton decay,
flavour changing neutral currents and large CP violation are ameliorated,
primarily due to the presence of an anomaly-free R-symmetry. Since
supersymmetry must be broken at a low scale, gravity-mediated effects which
break the R-symmetry are naturally small. The R-symmetry requires the presence
of adjoint chiral superfields, to give Dirac masses to the gauginos; these
adjoints are the only non-MSSM fields in the visible sector. The LSP is a very
light neutralino, which is mostly bino. Such a light neutralino is not in
conflict with experiment, and is a striking prediction of the minimal model.
Additional scenarios to raise the mass of this neutralino to the weak scale are
also outlined. Prospects for discovery at the LHC are briefly discussed, along
with viable scenarios for achieving gauge-coupling unification.Comment: 23 page
Kerr-Schild Ansatz in Lovelock Gravity

We analyze the field equations of Lovelock gravity for the Kerr-Schild metric
ansatz, $g_{ab}=\bar g_{ab} +\lambda k_ak_b$, with background metric $\bar
g_{ab}$, background null vector $k^a$ and free parameter $\lambda$. Focusing
initially on the Gauss-Bonnet case, we find a simple extension of the Einstein
gravity results only in theories having a unique constant curvature vacuum. The
field equations then reduce to a single equation at order $\lambda^2$. More
general Gauss-Bonnet theories having two distinct vacua yield a pair of
equations, at orders $\lambda$ and $\lambda^2$ that are not obviously
compatible. Our results for higher order Lovelock theories are less complete,
but lead us to expect a similar conclusion. Namely, the field equations for
Kerr-Schild metrics will reduce to a single equation of order $\lambda^p$ for
unique vacuum theories of order $p$ in the curvature, while non-unique vacuum
theories give rise to a set of potentially incompatible equations at orders
$\lambda^n$ with $1\le n \le p$. An examination of known static black hole
solutions also supports this conclusion.Comment: 14 pages; v2 reference adde
A Study on Charged Neutron Star in $AdS_5$

Motivated by an open question raised in recent times regarding the phase
transition during the collapse of a neutron star to form a black hole and
related stability issues, we have constructed charged neutron stars in $AdS_5$
and show that these stars become unstable at a particular value of their
radius, regarded as the Chandrasekhar radius. We reproduced the calculations
recently done in [20] in our $AdS_5$ charged star. The analysis shows that the
non-Fermi liquid behavior found there in $AdS_4$ is still true in this higher
dimensional case with the presence of Kosevich-Lifshitz oscillations.Comment: 20 pages, 6 figure
Wess-Zumino term in the N=4 SYM effective action revisited

The low-energy effective action for the N=4 super Yang-Mills on the Coulomb
branch is known to include an SO(6)-invariant Wess-Zumino (WZ) term for the six
scalar fields. For each maximal, non-anomalous subgroup of the SU(4)
R-symmetry, we find a four-dimensional form of the WZ term with this subgroup
being manifest. We then show that a recently proposed expression for the
four-derivative part of the effective action in N=4 USp(4) harmonic superspace
yields the WZ term with manifest SO(5) R-symmetry subgroup. The N=2 SU(2)
harmonic superspace form of the effective action produces the WZ term with
manifest SO(4) x SO(2). We argue that there is no four-dimensional form of the
WZ term with manifest SU(3) R-symmetry, which is relevant for N=1 and N=3
superspace formulations of the effective action.Comment: 26 pages; minor corrections and improvement
Large-N limits of 2d CFTs, Quivers and AdS_3 duals

We explore the large-N limits of 2d CFTs, focusing mostly on WZW models and
their cosets. The $SU(N)_k$ theory is parametrized in this limit by a 't
Hooft-like coupling. We show a duality between strong coupling, where the
theory is described by almost free fermions, and weak coupling where the theory
is described by bosonic fields by an analysis of spectra and correlators. The
AdS$_3$ dual is described, and several quantitative checks are performed.
Besides the more standard states that should correspond to bulk black holes we
find ground states with large degeneracy that can dominate the standard Cardy
entropy at weak coupling and are expected to correspond to regular horizonless
semiclassical bulk solutions.Comment: latex, 54pages; v2 minor changes, addition of a new appendix on YM-CS
  theories on AdS3, version published in JHEP; v3 several misprints have been
  corrected in the formulae of section
Holographic Conductivity in Disordered Systems

The main purpose of this paper is to holographically study the behavior of
conductivity in 2+1 dimensional disordered systems. We analyze probe D-brane
systems in AdS/CFT with random closed string and open string background fields.
We give a prescription of calculating the DC conductivity holographically in
disordered systems. In particular, we find an analytical formula of the
conductivity in the presence of codimension one randomness. We also
systematically study the AC conductivity in various probe brane setups without
disorder and find analogues of Mott insulators.Comment: 43 pages, 28 figures, latex, references added, minor correction