pinecone/core-2020-05-10-deduplication huggingface dataset:
R-charge conservation and more in factorizable and non-factorizable orbifolds

We consider the string theory origin of R-charge conservation laws in heterotic orbifold compactifications, deriving the corresponding string coupling selection rule for factorizable and non-factorizable orbifolds, with prime ordered and non-prime ordered point groups. R-charge conservation arises due to symmetries among the worldsheet instantons that can mediate the couplings. Among our results is a previously missed non-trivial contribution to the conserved R-charges from the gamma-phases in non-prime orbifolds, which weakens the R-charge selection rule. Symmetries among the worldsheet instantons can also lead to additional selection rules for some couplings. We make a similar analysis for Rule 4 or the "torus lattice selection rule". Moreover, we identify a new string selection rule, that we call Rule 6 or the "coset vector selection rule".CEADENCITMAEC/PITN-GA-2009-237920Ministry of Education, Culture, Sports, Science and Technology of JapanDFG/GRK/1463DFG/SFB/TR33EU/FP7/PITN-GA-2009-23792
An alternative IIB embedding of F(4) gauged supergravity

Through the construction of a complete non-linear Kaluza-Klein reduction
ansatz from type IIB supergravity to Romans' F(4) gauged supergravity, we
identify a recently discovered supersymmetric AdS_6 solution as the IIB uplift
of the supersymmetric vacuum of Romans' theory. We present new IIB uplifts of a
number of known solutions of Romans' theory and comment on supersymmetry in
higher-dimensions where it is expected.Comment: 39 pages, 1 figure, typos corrected, footnote added, references
  updated, to appear in JHE
Improving Electro-Weak Fits with TeV-scale Sterile Neutrinos

We study the impact of TeV-scale sterile neutrinos on electro-weak precision
observables and lepton number and flavour violating decays in the framework of
a type-I see-saw extension of the Standard Model. At tree level sterile
neutrinos manifest themselves via non-unitarity of the PMNS matrix and at
one-loop level they modify the oblique radiative corrections. We derive
explicit formulae for the S,T,U parameters in terms of the neutrino masses and
mixings and perform a numerical fit to the electro-weak observables. We find
regions of parameter space with a sizable active-sterile mixing which provide a
better over-all fit compared to the case where the mixing is negligible.
Specifically we find improvements of the invisible Z-decay width, the
charged-to-neutral-current ratio for neutrino scattering experiments and of the
deviation of the W boson mass from the theoretical expectation.Comment: 16 pages, 17 figures, Journal accepted versio
Thermal 2-loop master spectral function at finite momentum

When considering NLO corrections to thermal particle production in the “relativistic” regime, in which the invariant mass squared of the produced particle is K2 ~ (πT)2, then the production rate can be expressed as a sum of a few universal “master” spectral functions. Taking the most complicated 2-loop master as an example, a general strategy for obtaining a convergent 2-dimensional integral representation is suggested. The analysis applies both to bosonic and fermionic statistics, and shows that for this master the non-relativistic approximation is only accurate for K2 ~(8πT)2, whereas the zero-momentum approximation works surprisingly well. Once the simpler masters have been similarly resolved, NLO results for quantities such as the right-handed neutrino production rate from a Standard Model plasma or the dilepton production rate from a QCD plasma can be assembled for K2 ~ (πT)2
Exact Results in D=2 Supersymmetric Gauge Theories

We compute exactly the partition function of two dimensional N=(2,2) gauge
theories on S^2 and show that it admits two dual descriptions: either as an
integral over the Coulomb branch or as a sum over vortex and anti-vortex
excitations on the Higgs branches of the theory. We further demonstrate that
correlation functions in two dimensional Liouville/Toda CFT compute the S^2
partition function for a class of N=(2,2) gauge theories, thereby uncovering
novel modular properties in two dimensional gauge theories. Some of these gauge
theories flow in the infrared to Calabi-Yau sigma models - such as the conifold
- and the topology changing flop transition is realized as crossing symmetry in
Liouville/Toda CFT. Evidence for Seiberg duality in two dimensions is exhibited
by demonstrating that the partition function of conjectured Seiberg dual pairs
are the same.Comment: 78 pages, LaTeX; v2: small corrections and references added; v3: JHEP
  version, discussing factorization further in new appendix F; v4: sign
  corrected for non simply-connected gauge grou
D5-brane boundary reflection factors

We compute the strong coupling limit of the boundary reflection factor for
excitations on open strings attached to various kinds of D5-branes that probe
AdS5 x S5. We study the crossing equation, which constrains the boundary
reflection factor, and propose that some solutions will give the boundary
reflection factors for all values of the coupling. Our proposal passes various
checks in the strong coupling limit by comparison with diverse explicit string
theory computations. In some of the cases we consider, the D5-branes correspond
to 1/2 BPS Wilson loops in the k-th rank antisymmetric representation of the
dual field theory. In the other cases they correspond in the dual field theory
to the addition of a fundamental hypermultiplet in a defect.Comment: 32 pages, 3 figures. v2: minor changes and references adde
Searches for New Vector Like Quarks: Higgs Channels

New vector-like quarks can mix sizably with first generation Standard Model
quarks without conflicting with current experimental constraints. Searches for
such new quarks have been performed in pair production and electroweak single
production channels with subsequent decays into electroweak gauge bosons. To
fully explore the underlying structure of the theory the channels with heavy
quark decays into Higgs bosons are crucial and in this article we consider for
the first time the LHC reach for such channels. The two main production
mechanisms involve single production of new quarks through the fusion of a
vector boson and the Higgs and single production in association with a Higgs
boson. We show that both channels have promising reach at the LHC and that they
complement the current direct searches involving decays into electroweak gauge
bosons.Comment: 13 pages, 6 figures. V2: references added, matches published versio
Analytical study on holographic superconductors for Born-Infeld
  electrodynamics in Gauss-Bonnet gravity with backreactions

We analytically study the holographic superconductors for Born-Infeld
electrodynamics in Gauss-Bonnet gravity with backreactions. We note that the
analytic method is still powerful for this complex system and the results
obtained by the analytical and numerical computations are consistent. We find
that the critical temperature decreases with the increase of the backreactions,
Gauss-Bonnet, and Born-Infeld parameters, which means that increase of the
strength of these effects will make the scalar hair harder to form.
Furthermore, the Gauss-Bonnet factor modifies the critical temperature more
significantly than the backreaction factor. The effect of the Born-Infeld
factor on the critical temperature is weaker than the backreaction factor. We
also show that the critical exponent is not affected by the backreactions,
Gauss-Bonnet gravity, and Born-Infeld electrodynamics.Comment: 17 pages, 3 figures, 1 tal
Analytic structure of one-loop coefficients

By the unitarity cut method, analytic expressions of one-loop coefficients
have been given in spinor forms. In this paper, we present one-loop
coefficients of various bases in Lorentz-invariant contraction forms of
external momenta. Using these forms, the analytic structure of these
coefficients becomes manifest. Firstly, coefficients of bases contain only
second-type singularities while the first-type singularities are included
inside scalar bases. Secondly, the highest degree of each singularity is
correlated with the degree of the inner momentum in the numerator. Thirdly, the
same singularities will appear in different coefficients, thus our explicit
results could be used to provide a clear physical picture under various limits
(such as soft or collinear limits) when combining contributions from all bases.Comment: 40 pages. Some discussions and references update
Star Integrals, Convolutions and Simplices

We explore single and multi-loop conformal integrals, such as the ones
appearing in dual conformal theories in flat space. Using Mellin amplitudes, a
large class of higher loop integrals can be written as simple
integro-differential operators on star integrals: one-loop $n$-gon integrals in
$n$ dimensions. These are known to be given by volumes of hyperbolic simplices.
We explicitly compute the five-dimensional pentagon integral in full generality
using Schl\"afli's formula. Then, as a first step to understanding higher
loops, we use spline technology to construct explicitly the $6d$ hexagon and
$8d$ octagon integrals in two-dimensional kinematics. The fully massive hexagon
and octagon integrals are then related to the double box and triple box
integrals respectively. We comment on the classes of functions needed to
express these integrals in general kinematics, involving elliptic functions and
beyond.Comment: 23 page
Triality, periodicity and stability of SO(8) gauged supergravity

While electromagnetic duality is a symmetry of many supergravity theories, this is not the case for the N = 8 gauged theory. It was recently shown that this rotation leads to a one-parameter family of SO(8) supergravities. It is an open question what the period of this parameter is. This issue is investigated in the SO(4) invariant sectors of the theory. We classify such critical points and find a novel branch of non-supersymmetric and unstable solutions, whose embedding is related via triality to the two known ones. Secondly, we show that the three branches of solutions lead to a π/4 periodicity of the vacuum structure. The general interrelations between triality and periodicity are discussed. Finally, we comment on the connection to other gauge groups as well as the possibility to achieve (non-)perturbative stability around AdS/Mkw/dS transitions
Higgs-boson production at small transverse momentum

Using methods from effective field theory, we have recently developed a novel, systematic framework for the calculation of the cross sections for electroweak gauge-boson production at small and very small transverse momentum q T , in which large logarithms of the scale ratio m V /q T are resummed to all orders. This formalism is applied to the production of Higgs bosons in gluon fusion at the LHC. The production cross section receives logarithmically enhanced corrections from two sources: the running of the hard matching coefficient and the collinear factorization anomaly. The anomaly leads to the dynamical generation of a non-perturbative scale q∗~mHe−const/αs(mH)≈8 GeV, which protects the process from receiving large long-distance hadronic contributions. We present numerical predictions for the transverse-momentum spectrum of Higgs bosons produced at the LHC, finding that it is quite insensitive to hadronic effects
Single Top Events as a Source of Light Charged Higgs in the Fully
  Hadronic Final State at LHC

The single top production proceeds through different channels at LHC. The
t-channel production which has a cross section at the level of one third of the
ttbar, can be regarded as a source of light charged Higgs boson through top
quark decay to charged Higgs. Due to the low jet multiplicity and
characteristic kinematic features of this process, a signal selection can be
designed to extract charged Higgs signal from the background processes. In this
paper, taking MSSM as the theoretical framework, The light charged Higgs signal
from single top events is analyzed. The charged Higgs is assumed to decay to
tau nu and the hadronic decay of tau leptons is analyzed. Different charged
Higgs mass hypotheses are analyzed and a scan over the parameter space
(mH+,tanbeta) is performed. It is shown that this process has the potential to
exclude large areas of parameter space, while with enough data, a 5 sigma
discovery would also be possible. Finally 95% C.L. exclusion and 5 sigma
contours are provided for different integrated luminosities of LHC.Comment: 12 pages, 11 figure
The generalized cusp in ABJ(M) N = 6 Super Chern-Simons theories

We construct a generalized cusped Wilson loop operator in N = 6 super
Chern-Simons-matter theories which is locally invariant under half of the
supercharges. It depends on two parameters and interpolates smoothly between
the 1/2 BPS line or circle and a pair of antiparallel lines, representing a
natural generalization of the quark-antiquark potential in ABJ(M) theories. For
particular choices of the parameters we obtain 1/6 BPS configurations that,
mapped on S^2 by a conformal transformation, realize a three-dimensional
analogue of the wedge DGRT Wilson loop of N = 4. The cusp couples, in addition
to the gauge and scalar fields of the theory, also to the fermions in the
bifundamental representation of the U(N)xU(M) gauge group and its expectation
value is expressed as the holonomy of a suitable superconnection. We discuss
the definition of these observables in terms of traces and the role of the
boundary conditions of fermions along the loop. We perform a complete two-loop
analysis, obtaining an explicit result for the generalized cusp at the second
non-trivial order, from which we read off the interaction potential between
heavy 1/2 BPS particles in the ABJ(M) model. Our results open the possibility
to explore in the three-dimensional case the connection between localization
properties and integrability, recently advocated in D = 4.Comment: 53 pages, 10 figures, added references, this is the version appeared
  on JHE
Neutrino Mass from a d=7 Effective Operator in a SUSY-GUT Framework

Models, where neutrino mass originates from physics at the TeV scale and
which are potentially testable at the LHC, need additional suppression
mechanisms to describe the smallness of neutrino masses. We consider models in
which neutrino mass is generated from the d=7 operator $L L H_u H_u H_d H_u$ in
the context of SUSY-GUTs containing an SU(5) subgroup, here the d=5 Weinberg
operator can be forbidden by a discrete symmetry. That is, we identify the
embeddings in GUT multiplets and their consequences for phenomenology and
renormalization group evolution. We use a specific example to exemplify the
challenges. In this case, additional heavy d-quarks are predicted, which are
constrained by cosmology, in particular, by big bang nucleosynthesis and direct
searches for heavy nuclei. We show that in the NMSSM extension of the model,
the discrete symmetry needs to be broken, which can be the origin of deviations
from tri-bimaximal mixings. Finally we demonstrate that our example is the only
tree level decomposition which is consistent with perturbativity up to the GUT
scale and neutrino mass generation by a leading d=7 contribution.Comment: 16 pages, 1 figure, 4 table
Non-Abelian Tensor Towers and (2,0) Superconformal Theories

With the aim to study six-dimensional (2,0) superconformal theories with
non-Abelian tensor multiplets we propose a five-dimensional superconformal
action with eight supersymmetries for an infinite tower of non-Abelian vector,
tensor and hypermultiplets. It describes the dynamics of the complete spectrum
of the (2,0) theories compactified on a circle coupled to an additional vector
multiplet containing the circle radius and the Kaluza-Klein vector arising from
the six-dimensional metric. All couplings are only given in terms of group
theoretical constants and the Kaluza-Klein levels. After superconformal
symmetry is reduced to Poincare supersymmetry we find a Kaluza-Klein inspired
action coupling super-Yang-Mills theory to an infinite tower of massive
non-Abelian tensors. We explore the possibility to restore sixteen
supersymmetries by using techniques known from harmonic superspace. Namely,
additional bosonic coordinates on a four-sphere are introduced to enhance the
R-symmetry group. Maximally supersymmetric Yang-Mills theories and the Abelian
(2,0) tensor theories are recovered as special cases of our construction.
Finally, we comment on the generation of an anomaly balancing Wess-Zumino term
for the R-symmetry vector at one loop.Comment: 55 pages, 5 figures; v2: minus sign in eq. (4.13) fixed, final action
  (4.20) adjusted, references adde
Auxiliary superfields in N=1 supersymmetric self-dual electrodynamics

We construct the general formulation of N = 1 supersymmetric self-dual abelian gauge theory involving auxiliary chiral spinor superfields. Self-duality in this context is just U(N) invariance of the nonlinear interaction of the auxiliary superfields. Focusing on the U(1) case, we present the most general form of the U(1) invariant auxiliary interaction, consider a few instructive examples and show how to generate self-dual N = 1 models with higher derivatives in this approach.RFBR/12-02-00517DFG/LE 838/12-1Heisenberg-Landau progra
Thermalization of causal holographic information.

We study causal wedges associated with a given sub-region in the boundary of asymptotically AdS spacetimes. Part of our motivation is to better understand the recently proposed holographic observable, causal holographic information, χ, which is given by the area of a bulk co-dimension two surface lying on the boundary of the causal wedge. It has been suggested that χ captures the basic amount of information contained in the reduced density matrix about the bulk geometry. To explore its properties further we examine its behaviour in time-dependent situations. As a simple model we focus on null dust collapse in an asymptotically AdS spacetime, modeled by the Vaidya-AdS geometry. We argue that while χ is generically quasi-telelogical in time-dependent backgrounds, for suitable choice of sub-regions in conformal field theories, the temporal evolution of χ is entirely causal. We comment on the implications of this observation and more generally on features of causal constructions and contrast our results with the behaviour of holographic entanglement entropy. Along the way we also derive the rate of early time growth and late time saturation (to the thermal value) of both χ and entanglement entropy in these backgrounds
Tensionless strings and Galilean Conformal Algebra

We discuss an intriguing link between the symmetries of the tensionless limit of closed string theory and the 2-dimensional Galilean Conformal Algebra (2d GCA). 2d GCA has been studied in the context of the non-relativistic limit of AdS/CFT and more recently in flat-space holography as the proposed symmetry algebra of the field theory dual to 3d Minkowski spacetimes. It is best understood as a contraction of two copies of the Virasoro algebra. In this note, we link this to the tensionless limit of bosonic closed string theory showing how it emerges naturally as a contraction of the residual gauge symmetries of the tensile string in the conformal gauge. We also discuss a possible “dual” interpretation in terms of a point-particle like limit. We show that this different contraction, motivated by an exchange of world-sheet space and time co-ordinates, leads to the same symmetry algebra and provide further evidence in support of our claim by looking at the theory on a torus.Engineering and Physical Sciences Research CouncilScottish University Physics Alliance (Early Career Grant)Edinburgh Partnership in Engineering and Mathematics (Early Career Grant
Thermal Evolution of the Non Supersymmetric Metastable Vacua in N=2
  SU(2) SYM Softly Broken to N=1

It has been shown that four dimensional N=2 gauge theories, softly broken to
N=1 by a superpotential term, can accommodate metastable non-supersymmetric
vacua in their moduli space. We study the SU(2) theory at high temperatures in
order to determine whether a cooling universe settles in the metastable vacuum
at zero temperature. We show that the corrections to the free energy because of
the BPS dyons are such that may destroy the existence of the metastable vacuum
at high temperatures. Nevertheless we demonstrate the universe can settle in
the metastable vacuum, provided that the following two conditions are hold:
first the superpotential term is not arbitrarily small in comparison to the
strong coupling scale of the gauge theory, and second the metastable vacuum
lies in the strongly coupled region of the moduli space.Comment: 32 pages, 30 figure
Renormalization group running of dimension-six sources of parity and time-reversal violation

We perform a systematic study of flavor-diagonal parity- and time-reversal-violating operators of dimension six which could arise from physics beyond the SM. We begin at the unknown high-energy scale where these operators originate. At this scale the operators are constrained by gauge invariance which has important consequences for the form of effective operators at lower energies. In particular for the four-quark operators. We calculate one-loop QCD and, when necessary, electroweak corrections to the operators and evolve them down to the electroweak scale and subsequently to hadronic scales. We find that for most operators QCD corrections are not particularly significant. We derive a set of operators at low energy which is expected to dominate hadronic and nuclear EDMs due to physics beyond the SM and obtain quantitative relations between these operators and the original dimension-six operators at the high-energy scale. We use the limit on the neutron EDM to set bounds on the dimension-six operators
On Composite Two Higgs Doublet Models

We investigate composite two Higgs doublet models realized as pseudo
Goldstone modes, generated through the spontaneous breaking of a global
symmetry due to strong dynamic at the TeV scale. A detailed comparative survey
of two possible symmetry breaking patterns, SU(5) -> SU(4) x U(1) and SU(5) x
SU(4), is made. We point out choices for the Standard Model fermion
representations that can alleviate some phenomenological constraints, with
emphasis towards a simultaneous solution of anomalous Zb\bar{b} coupling and
Higgs mediated Flavor Changing Neutral Currents. We also write down the kinetic
lagrangian for several models leading to Two Higgs Doublets and identify the
anomalous contributions to the T parameter. Moreover, we describe a model based
on the breaking $SO(9)/SO(8)$ in which there is no tree-level breaking of
custodial symmetry, discussing also the possible embeddings for the fermion
fields.Comment: 17 pages. Mistake corrected, added one section on a T- and flavor
  safe model based on SO(9)/SO(8). Matches published versio
Constraints on a Very Light Sbottom

We investigate the phenomenological viability of a very light bottom squark,
with a mass less than half of the Z boson mass. The decays of the Z and Higgs
bosons to light sbottom pairs are, in a fairly model independent manner,
strongly constrained by the precision electroweak data and Higgs signal
strength measurements, respectively. These constraints are complementary to
direct collider searches, which depend in detail on assumptions regarding the
superpartner spectrum and decays of the sbottom. In particular, if the lightest
sbottom has a mass below about 15 GeV, compatibility with these measurements is
possible only in a special region of parameter space in which the couplings of
the lightest sbottom to the Z and Higgs are suppressed. In this region, the
second sbottom is predicted to be lighter than about 300 GeV and can also be
searched for directly at the LHC. We also survey relevant collider searches for
canonical scenarios with a bino, gravitino, or singlino LSP in the compressed
and stealth kinematic regimes and provide suggestions to cover remaining open
regions of parameter space.Comment: 37 page