pinecone/core-2020-05-10-deduplication huggingface dataset:
Impact of massive neutrinos on the Higgs self-coupling and electroweak
  vacuum stability

The presence of right-handed neutrinos in the type I seesaw mechanism may
lead to significant corrections to the RG evolution of the Higgs self-coupling.
Compared to the Standard Model case, the Higgs mass window can become narrower,
and the cutoff scale become lower. Naively, these effects decrease with
decreasing right-handed neutrino mass. However, we point out that the unknown
Dirac Yukawa matrix may impact the vacuum stability constraints even in the low
scale seesaw case not far away from the electroweak scale, hence much below the
canonical seesaw scale of 10^15 GeV. This includes situations in which
production of right-handed neutrinos at colliders is possible. We illustrate
this within a particular parametrization of the Dirac Yukawas and with explicit
low scale seesaw models. We also note the effect of massive neutrinos on the
top quark Yukawa coupling, whose high energy value can be increased with
respect to the Standard Model case.Comment: 17 pages, 7 figures, minor revisions, version to appear in JHE
Quantization of area for event and Cauchy horizons of the Kerr-Newman
  black hole

Based on various string theoretic constructions, and various string-inspired
generalizations thereof, there have been repeated suggestions that the areas of
black hole event horizons might be quantized in a quite specific manner, in
terms of linear combinations of square roots of positive integers. It is
important to realise that there are significant physical constraints on such
integer-based proposals when one (somewhat speculatively) attempts to extend
them outside their original extremal and supersymmetric framework.
Specifically, in their most natural and direct physical interpretations, some
of the more speculative integer-based proposals for the quantization of horizon
areas fail for the ordinary Kerr-Newman black holes in (3+1) dimensions,
essentially because the fine structure constant is not an integer. A more
baroque interpretation involves asserting the fine structure constant is the
square root of a rational number; but such a proposal has its own problems.
Insofar as one takes (3+1) general relativity (plus the usual quantization of
angular momentum and electric charge) as being paramount, the known explicitly
calculable spectra of horizon areas for the physically compelling Kerr-Newman
spacetimes indicate that some caution is called for when assessing the
universality of some of the more speculative integer-based string-inspired
proposals.Comment: v1: 15 pages; v2: 2 references added, no physics changes; v3: 16 now
  pages, discussion of physical implications clarified, no calculational
  changes, this version accepted for publication in JHE
Spatially homogeneous Lifshitz black holes in five dimensional higher
  derivative gravity

We consider spatially homogeneous Lifshitz black hole solutions in five
dimensional higher derivative gravity theories, which can be possible near
horizon geometries of some systems that are interesting in the framework of
gauge/gravity duality. We show the solutions belonging to the nine Bianchi
classes in the pure R^2 gravity. We find that these black holes have zero
entropy at non-zero temperatures and this property is the same as the case of
BTZ black holes in new massive gravity at the critical point. In the most
general quadratic curvature gravity theories, we find new solutions in Bianchi
Type I and Type IX cases.Comment: 15 pages, no figure; v2, refs added, version to appear in JHE
Vortex counting from field theory

The vortex partition function in 2d N = (2,2) U(N) gauge theory is derived
from the field theoretical point of view by using the moduli matrix approach.
The character for the tangent space at each moduli space fixed point is written
in terms of the moduli matrix, and then the vortex partition function is
obtained by applying the localization formula. We find that dealing with the
fermionic zero modes is crucial to obtain the vortex partition function with
the anti-fundamental and adjoint matters in addition to the fundamental chiral
multiplets. The orbifold vortex partition function is also investigated from
the field theoretical point of view.Comment: 21 pages, no figure
On cosmological constants from α′-corrections

We examine to what extent perturbative α′-corrections can generate a small cosmological constant in warped string compactifications. Focusing on the heterotic string at lowest order in the string loop expansion, we show that, for a maximally symmetric spacetime, the α′-corrected 4D scalar potential has no effect on the cosmological constant. The only relevant terms are instead higher order products of 4D Riemann tensors, which, however, are found to vanish in the usual perturbative regime of the α′-expansion. The heterotic string therefore only allows for 4D Minkowski vacua to all orders in α′, unless one also introduces string loop and/or nonperturbative corrections or allows for curvatures or field strengths that are large in string units. In particular, we find that perturbative α′-effects cannot induce weakly curved AdS4 solutions.DFG/EXC/QUES
Stabilization of the Electroweak Vacuum by a Scalar Threshold Effect

We show how a heavy scalar singlet with a large vacuum expectation value can
evade the potential instability of the Standard Model electroweak vacuum. The
quartic interaction between the heavy scalar singlet and the Higgs doublet
leads to a positive tree-level threshold correction for the Higgs quartic
coupling, which is very effective in stabilizing the potential. We provide
examples, such as the see-saw, invisible axion and unitarized Higgs inflation,
where the proposed mechanism is automatically implemented in well-defined
ranges of Higgs masses.Comment: 18 pages, 5 figure
Supersymmetry with Light Stops

Recent LHC data, together with the electroweak naturalness argument, suggest
that the top squarks may be significantly lighter than the other sfermions. We
present supersymmetric models in which such a split spectrum is obtained
through "geometries": being "close to" electroweak symmetry breaking implies
being "away from" supersymmetry breaking, and vice versa. In particular, we
present models in 5D warped spacetime, in which supersymmetry breaking and
Higgs fields are located on the ultraviolet and infrared branes, respectively,
and the top multiplets are localized to the infrared brane. The hierarchy of
the Yukawa matrices can be obtained while keeping near flavor degeneracy
between the first two generation sfermions, avoiding stringent constraints from
flavor and CP violation. Through the AdS/CFT correspondence, the models can be
interpreted as purely 4D theories in which the top and Higgs multiplets are
composites of some strongly interacting sector exhibiting nontrivial dynamics
at a low energy. Because of the compositeness of the Higgs and top multiplets,
Landau pole constraints for the Higgs and top couplings apply only up to the
dynamical scale, allowing for a relatively heavy Higgs boson, including m_h =
125 GeV as suggested by the recent LHC data. We analyze electroweak symmetry
breaking for a well-motivated subset of these models, and find that fine-tuning
in electroweak symmetry breaking is indeed ameliorated. We also discuss a flat
space realization of the scenario in which supersymmetry is broken by boundary
conditions, with the top multiplets localized to a brane while other matter
multiplets delocalized in the bulk.Comment: 27 pages, 7 figure
Canonical approach to Courant brackets for D-branes

We present an extension of the Courant bracket to the ones for Dp-branes by
analyzing Hamiltonians and local superalgebras. Contrast to the basis of the
bracket for a fundamental string which consists of the momentum and the winding
modes, the ones for Dp-branes contain higher rank R-R coupling tensors. We show
that the R-R gauge transformation rules are obtained by these Courant brackets
for Dp-branes where the Dirac-Born-Infeld gauge field and the "two-vierbein
field" play an essential role. Canonical analysis of the worldvolume theories
naturally gives the basis of the brackets and the target space backgrounds
keeping T-duality manifest at least for NS-NS sector. In a D3-brane analysis
S-duality is manifest as a symmetry of interchanging the NS-NS coupling and the
R-R coupling.Comment: 27 pages, ver2: typos corrected, references added, ver3: R-R gauge
  vectors are corrected, ver4: Contribution of the canonical bracket for DBI
  fields is adde
A note on perturbation series in supersymmetric gauge theories

Exact results in supersymmetric Chern-Simons and N=2 Yang-Mills theories can
be used to examine the quantum behavior of observables and the structure of the
perturbative series. For the U(2) x U(2) ABJM model, we determine the
asymptotic behavior of the perturbative series for the partition function and
write it as a Borel transform. Similar results are obtained for N=2 SU(2) super
Yang-Mills theory with four fundamental flavors and in N=2* super Yang-Mills
theory, for the partition function as well as for the expectation values for
Wilson loop and 't Hooft loop operators (in the 0 and 1 instanton sectors). In
all examples, one has an alternate perturbation series where the coefficient of
the nth term increases as n!, and the perturbation series are Borel summable.
We also calculate the expectation value for a Wilson loop operator in the N=2*
SU(N) theory at large N in different regimes of the 't Hooft gauge coupling and
mass parameter. For large masses, the calculation reproduces the running gauge
coupling for the pure N=2 SYM theory.Comment: 28 pages. V2: minor additions and reference adde
Search for charged Higgs bosons decaying via H± → τν in tt̄ events using pp collision data at √s = 7 TeV with the ATLAS detector

Journal of High Energy Physics 2012.6 (2012): 039 reproduced by permission of Scuola Internazionale Superiore di Studi Avanzati (SISSA)Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMThe results of a search for charged Higgs bosons are presented. The analysis is based on 4.6 fb-1 of proton-proton collision data at √s = 7TeV collected by the ATLAS experiment at the Large Hadron Collider, using top quark pair events with a τ lepton in the final state. The data are consistent with the expected background from Standard Model processes. Assuming that the branching ratio of the charged Higgs boson to a τ lepton and a neutrino is 100%, this leads to upper limits on the branching ratio of top quark decays to a b quark and a charged Higgs boson between 5% and 1% for charged Higgs boson masses ranging from 90GeV to 160GeV, respectively. In the context of the mh maxscenario of the MSSM, tan β above 12-26, as well as between 1 and 2-6, can be excluded for charged Higgs boson masses between 90GeV and 150Ge
Parity Violating Statistical Anisotropy

Particle production of an Abelian vector boson field with an axial coupling
is investigated. The conditions for the generation of scale invariant spectra
for the vector field transverse components are obtained. If the vector field
contributes to the curvature perturbation in the Universe, scale-invariant
particle production enables it to give rise to statistical anisotropy in the
spectrum and bispectrum of cosmological perturbations. The axial coupling
allows particle production to be parity violating, which in turn can generate
parity violating signatures in the bispectrum. The conditions for parity
violation are derived and the observational signatures are obtained in the
context of the vector curvaton paradigm. Two concrete examples are presented
based on realistic particle theory.Comment: Accepted for publication in JHE
Constraints on Universal Extra Dimension models with gravity mediated
  decays from ATLAS diphoton search

We discuss the collider phenomenology of Universal Extra Dimension models
with gravity mediated decays. We concentrate on diphoton associated with large
missing transverse energy signature. At the collider, level-1 Kaluza-Klein (KK)
particles are produced in pairs due to the conservation of KK-parity.
Subsequently, KK-particles decay via cascades involving lighter KK-particles
until reaching the lightest KK-particle (LKP). Finally, gravity induced decay
of the LKP into photons gives rise to the diphoton signature. The search for
diphoton events with large missing transverse energy was recently communicated
by the ATLAS collaboration for 7 TeV center-of-mass energy and 3.1 inverse
femtobarn integrated luminosity of the Large Hadron Collider. Above the
Standard Model background prediction, no excess of such events was reported. We
translate the absence of any excess of the diphoton events to constrain the
model parameters, namely, the radius of compactification (R) and the
fundamental Planck mass ($M_D$).Comment: 24 pages, 10 figure
Parton shower evolution with subleading color

Parton shower Monte Carlo event generators in which the shower evolves from
hard splittings to soft splittings generally use the leading color
approximation, which is the leading term in an expansion in powers of
$1/N_c^2$, where $N_c = 3$ is the number of colors. We introduce a more general
approximation, the LC+ approximation, that includes some of the color
suppressed contributions. There is a cost: each generated event comes with a
weight. There is a benefit: at each splitting the leading soft$\times$collinear
singularity and the leading collinear singularity are treated exactly with
respect to color. In addition, an LC+ shower can start from a state of the
color density matrix in which the bra state color and the ket state color do
not match.Comment: 50 pages with 16 figures. Revised to improve clarit
Flavor Mediation Delivers Natural SUSY

If supersymmetry (SUSY) solves the hierarchy problem, then naturalness
considerations coupled with recent LHC bounds require non-trivial superpartner
flavor structures. Such "Natural SUSY" models exhibit a large mass hierarchy
between scalars of the third and first two generations as well as degeneracy
(or alignment) among the first two generations. In this work, we show how this
specific beyond the standard model (SM) flavor structure can be tied directly
to SM flavor via "Flavor Mediation". The SM contains an anomaly-free SU(3)
flavor symmetry, broken only by Yukawa couplings. By gauging this flavor
symmetry in addition to SM gauge symmetries, we can mediate SUSY breaking via
(Higgsed) gauge mediation. This automatically delivers a natural SUSY spectrum.
Third-generation scalar masses are suppressed due to the dominant breaking of
the flavor gauge symmetry in the top direction. More subtly, the
first-two-generation scalars remain highly degenerate due to a custodial U(2)
symmetry, where the SU(2) factor arises because SU(3) is rank two. This
custodial symmetry is broken only at order (m_c/m_t)^2. SUSY gauge coupling
unification predictions are preserved, since no new charged matter is
introduced, the SM gauge structure is unaltered, and the flavor symmetry treats
all matter multiplets equally. Moreover, the uniqueness of the anomaly-free
SU(3) flavor group makes possible a number of concrete predictions for the
superpartner spectrum.Comment: 17 pages, 7 figures, 2 tables. v2 references added, minor changes to
  flavor constraints and a little discussion adde
Bekenstein entropy bound for weakly-coupled field theories on a 3-sphere

We calculate the high temperature partition functions for SU(Nc) or U(Nc)
gauge theories in the deconfined phase on S^1 x S^3, with scalars, vectors,
and/or fermions in an arbitrary representation, at zero 't Hooft coupling and
large Nc, using analytical methods. We compare these with numerical results
which are also valid in the low temperature limit and show that the Bekenstein
entropy bound resulting from the partition functions for theories with any
amount of massless scalar, fermionic, and/or vector matter is always satisfied
when the zero-point contribution is included, while the theory is sufficiently
far from a phase transition. We further consider the effect of adding massive
scalar or fermionic matter and show that the Bekenstein bound is satisfied when
the Casimir energy is regularized under the constraint that it vanishes in the
large mass limit. These calculations can be generalized straightforwardly for
the case of a different number of spatial dimensions.Comment: 32 pages, 12 figures. v2: Clarifications added. JHEP versio
An exact formula for the radiation of a moving quark in N=4 super Yang
  Mills

We derive an exact formula for the cusp anomalous dimension at small angles.
This is done by relating the latter to the computation of certain 1/8 BPS
Wilson loops which was performed by supersymmetric localization. This function
of the coupling also determines the power emitted by a moving quark in N=4
super Yang Mills, as well as the coefficient of the two point function of the
displacement operator on the Wilson loop. By a similar method we compute the
near BPS expansion of the generalized cusp anomalous dimension.Comment: 22 pages, 5 figures. v2: references added, typos correcte
Infinite dimension reflection matrices in the sine-Gordon model with a
  boundary

Using the sine-Gordon model as the prime example an alternative approach to
integrable boundary conditions for a theory restricted to a half-line is
proposed. The main idea is to explore the consequences of taking into account
the topological charge residing on the boundary and the fact it changes as
solitons in the bulk reflect from the boundary. In this context, reflection
matrices are intrinsically infinite dimensional, more general than the
two-parameter Ghoshal-Zamolodchikov reflection matrix, and related in an
intimate manner with defects.Comment: 11 pages, typos corrected, reference added, paragraph added at the
  end of section
Topological susceptibility on the lattice and the three-flavour quark
  condensate

We reanalyse the topological susceptibility assuming the possibility of a
significant paramagnetic suppression of the three-flavour quark condensate and
a correlated enhancement of vacuum fluctuations of $s\bar{s}$ pairs. Using the
framework of resummed ChPT, we point out that simulations performed near the
physical point, with a significant mass hierarchy between u,d and s dynamical
quarks, are not able to disentangle the contributions from the quark condensate
and sea $s\bar{s}$-pair fluctuations, and that simulations with three light
quark masses of the same order are better suited for this purpose. We perform a
combined fit of recent RBC/UKQCD data on pseudoscalar masses and decay
constants as well as the topological susceptibility, and we reconsider the
determination of lattice spacings in our framework, working out the
consequences on the parameters of the chiral Lagrangian. We obtain Sigma(3;2
GeV)^1/3=243 \pm 12 MeV for the three-flavour quark condensate in the chiral
limit. We notice a significant suppression compared to the two-flavour quark
condensate Sigma(2;2 GeV)/Sigma(3;2 GeV)=1.51\pm 0.11 and we confirm previous
findings of a competition between leading order and next-to-leading order
contributions in three-flavour chiral series.Comment: 6 figures, 29 pages. Extended discussion of lattice artefacts.
  Accepted for publication in JHE
NLL soft and Coulomb resummation for squark and gluino production at the
  LHC

We present predictions of the total cross sections for pair production of
squarks and gluinos at the LHC, including the stop-antistop production process.
Our calculation supplements full fixed-order NLO predictions with resummation
of threshold logarithms and Coulomb singularities at next-to-leading
logarithmic (NLL) accuracy, including bound-state effects. The numerical effect
of higher-order Coulomb terms can be as big or larger than that of soft-gluon
corrections. For a selection of benchmark points accessible with data from the
2010-2012 LHC runs, resummation leads to an enhancement of the total inclusive
squark and gluino production cross section in the 15-30 % range. For individual
production processes of gluinos, the corrections can be much larger. The
theoretical uncertainty in the prediction of the hard-scattering cross sections
is typically reduced to the 10 % level.Comment: 45 pages, 16 Figures, LaTex. v2: published version. Grids with
  numerical results for the NLL cross sections for squark and gluino production
  at the 7/8 TeV LHC are included in the submission and are also available at
  http://omnibus.uni-freiburg.de/~cs1010/susy.htm
Eisenstein series for infinite-dimensional U-duality groups

We consider Eisenstein series appearing as coefficients of curvature
corrections in the low-energy expansion of type II string theory four-graviton
scattering amplitudes. We define these Eisenstein series over all groups in the
E_n series of string duality groups, and in particular for the
infinite-dimensional Kac-Moody groups E9, E10 and E11. We show that,
remarkably, the so-called constant term of Kac-Moody-Eisenstein series contains
only a finite number of terms for particular choices of a parameter appearing
in the definition of the series. This resonates with the idea that the constant
term of the Eisenstein series encodes perturbative string corrections in
BPS-protected sectors allowing only a finite number of corrections. We underpin
our findings with an extensive discussion of physical degeneration limits in
D<3 space-time dimensions.Comment: 69 pages. v2: Added references and small additions, to be published
  in JHE
Vacuum Stability Bound on Extended GMSB Models

Extensions of GMSB models were explored to explain the recent reports of the
Higgs boson mass around 124-126 GeV. Some models predict a large mu term, which
can spoil the vacuum stability of the universe. We study two GMSB extensions:
i) the model with a large trilinear coupling of the top squark, and ii) that
with extra vector-like matters. In both models, the vacuum stability condition
provides upper bounds on the gluino mass if combined with the muon g-2. The
whole parameter region is expected to be covered by LHC at sqrt{s} = 14 TeV.
The analysis is also applied to the mSUGRA models with the vector-like matters.Comment: 22 pages, 4 figure
Algebras for Amplitudes

Tree-level amplitudes of gauge theories are expressed in a basis of auxiliary
amplitudes with only cubic vertices. The vertices in this formalism are
explicitly factorized in color and kinematics, clarifying the color-kinematics
duality in gauge theory amplitudes. The basis is constructed making use of the
KK and BCJ relations, thereby showing precisely how these relations underlie
the color-kinematics duality. We express gravity amplitudes in terms of a
related basis of color-dressed gauge theory amplitudes, with basis coefficients
which are permutation symmetric.Comment: 17 pages, 1 figure. v2: published version, example added in appendi