pinecone/core-2020-05-10-deduplication huggingface dataset:
One-loop Higgs plus four gluon amplitudes: Full analytic results

We consider one-loop amplitudes of a Higgs boson coupled to gluons in the limit of a large top quark mass. We treat the Higgs as the real part of a complex field phi that couples to the self-dual field strengths and compute the one-loop corrections to the phi-NMHV amplitude, which contains one gluon of positive helicity whilst the remaining three have negative helicity. We use four-dimensional unitarity to construct the cut-containing contributions and a hybrid of Feynman diagram and recursive based techniques to determine the rational piece. Knowledge of the phi-NMHV contribution completes the analytic calculation of the Higgs plus four gluon amplitude. For completeness we also include expressions for the remaining helicity configurations which have been calculated elsewhere. These amplitudes are relevant for Higgs plus jet production via gluon fusion in the limit where the top quark is large compared to all other scales in the problem
Combining Anomaly and Z' Mediation of Supersymmetry Breaking

We propose a scenario in which the supersymmetry breaking effect mediated by
an additional U(1)' is comparable with that of anomaly mediation. We argue that
such a scenario can be naturally realized in a large class of models. Combining
anomaly with Z' mediation allows us to solve the tachyonic slepton problem of
the former and avoid significant fine tuning in the latter. We focus on an
NMSSM-like scenario where U(1)' gauge invariance is used to forbid a tree-level
mu term, and present concrete models, which admit successful dynamical
electroweak symmetry breaking. Gaugino masses are somewhat lighter than the
scalar masses, and the third generation squarks are lighter than the first two.
In the specific class of models under consideration, the gluino is light since
it only receives a contribution from 2-loop anomaly mediation, and it decays
dominantly into third generation quarks. Gluino production leads to distinct
LHC signals and prospects of early discovery. In addition, there is a
relatively light Z', with mass in the range of several TeV. Discovering and
studying its properties can reveal important clues about the underlying model.Comment: Minor changes: references added, typos corrected, journal versio
Extremal black holes, nilpotent orbits and the true fake superpotential

Dimensional reduction along time offers a powerful way to study stationary
solutions of 4D symmetric supergravity models via group-theoretical methods. We
apply this approach systematically to extremal, BPS and non-BPS, spherically
symmetric black holes, and obtain their "fake superpotential" W. The latter
provides first order equations for the radial problem, governs the mass and
entropy formula and gives the semi-classical approximation to the radial wave
function. To achieve this goal, we note that the Noether charge for the radial
evolution must lie in a certain Lagrangian submanifold of a nilpotent orbit of
the 3D continuous duality group, and construct a suitable parametrization of
this Lagrangian. For general non-BPS extremal black holes in N=8 supergravity,
W is obtained by solving a non-standard diagonalization problem, which reduces
to a sextic polynomial in $W^2$ whose coefficients are SU(8) invariant
functions of the central charges. By consistent truncation we obtain W for
other supergravity models with a symmetric moduli space. In particular, for the
one-modulus $S^3$ model, $W^2$ is given explicitely as the root of a cubic
polynomial. The STU model is investigated in detail and the nilpotency of the
Noether charge is checked on explicit solutions.Comment: 47 pages + appendices, 7 figures; v2: minor corrections, to appear in
  JHE
Canonical Analysis of Algebraic String Actions

We investigate the canonical aspects of the algebraic first order formulation
of strings introduced two decades ago by Balachandran and collaborators. We
slightly enlarge the Lagrangian framework and show the existence of a self-dual
formulation and of an Immirzi-type parameter reminiscent of four-dimensional
first order gravity. We perform a full Hamiltonian analysis of the self-dual
case: we extract the first class constraints and construct the Dirac bracket
associated to the second class constraints. The first class constraints contain
the diffeomorphisms algebra on the world-sheet, and the coordinates are shown
to be non-commutative with respect to the Dirac bracket. The Hamilton equations
in a particular gauge are shown to reproduce the wave equation for the string
coordinates. In the general, non-self-dual case, we also explicit the first
class constraints of the system and show that, unlike the self-dual
formulation, the theory admits an extra propagating degree of freedom than the
two degrees of freedom of conventional string theory. This prevents the general
algebraic string from being strictly equivalent to the Nambu-Goto string.Comment: Title changed. Presentation improved. Typos correcte
D-instantons and multiparticle production in N=4 SYM

N=4 Super-symmetric Yang-Mills theory (N=4 SYM) in the strong coupling regime
has been successfully applied (through the AdS/CFT correspondence) to the
description of strongly coupled plasma which is a multiparticle state. Yet, the
high-energy scattering in the strong coupling limit of N=4 SYM is purely
elastic, so this multiparticle final state can never be produced: this is
because in this limit the theory is dual to weak supergravity, and the dominant
interaction is the elastic graviton exchange. Here we propose a resolution of
this dilemma by considering the contribution of D-instantons in $AdS_5$ bulk
space to the scattering amplitude. We argue that D-instantons coupled to
dilatons and axions are responsible for multiparticle production in strongly
coupled N=4 SYM, and the corresponding cross section increases with energy. We
evaluate the intercept and the slope of the corresponding Pomeron trajectory in
terms of the typical size of the D-instanton, and argue that the resulting
physical picture may resemble the real world.Comment: 22 pp and 11 figures in the eps forma
Measuring Slepton Masses and Mixings at the LHC

Flavor physics may help us understand theories beyond the standard model. In
the context of supersymmetry, if we can measure the masses and mixings of
sleptons and squarks, we may learn something about supersymmetry and
supersymmetry breaking. Here we consider a hybrid gauge-gravity supersymmetric
model in which the observed masses and mixings of the standard model leptons
are explained by a U(1) x U(1) flavor symmetry. In the supersymmetric sector,
the charged sleptons have reasonably large flavor mixings, and the lightest is
metastable. As a result, supersymmetric events are characterized not by missing
energy, but by heavy metastable charged particles. Many supersymmetric events
are therefore fully reconstructible, and we can reconstruct most of the charged
sleptons by working up the long supersymmetric decay chains. We obtain
promising results for both masses and mixings, and conclude that, given a
favorable model, precise measurements at the LHC may help shed light not only
on new physics, but also on the standard model flavor parameters.Comment: 24 pages; v2: fixed a typo in our computer program that led to some
  miscalculated branching ratios, various clarifications and minor
  improvements, conclusions unchanged, published versio
Sequences of dipole black rings and Kaluza-Klein bubbles

We construct new exact solutions to 5D Einstein-Maxwell equations describing
sequences of Kaluza-Klein bubbles and dipole black rings. The solutions are
generated by 2-soliton transformations from vacuum black ring - bubble
sequences. The properties of the solutions are investigated. We also derive the
Smarr-like relations and the mass and tension first laws in the general case
for such configurations of Kaluza-Klein bubbles and dipole black rings. The
novel moment is the appearance of the magnetic flux in the Smarr-like relations
and the first laws.Comment: 26 pages, 1 figur
Simplicity of Polygon Wilson Loops in N=4 SYM

Wilson loops with lightlike polygonal contours have been conjectured to be
equivalent to MHV scattering amplitudes in N=4 super Yang-Mills. We compute
such Wilson loops for special polygonal contours at two loops in perturbation
theory. Specifically, we concentrate on the remainder function R, obtained by
subtracting the known ABDK/BDS ansatz from the Wilson loop. First, we consider
a particular two-dimensional eight-point kinematics studied at strong coupling
by Alday and Maldacena. We find numerical evidence that R is the same at weak
and at strong coupling, up to an overall, coupling-dependent constant. This
suggests a universality of the remainder function at strong and weak coupling
for generic null polygonal Wilson loops, and therefore for arbitrary MHV
amplitudes in N=4 super Yang-Mills. We analyse the consequences of this
statement. We further consider regular n-gons, and find that the remainder
function is linear in n at large n through numerical computations performed up
to n=30. This reproduces a general feature of the corresponding strong-coupling
result.Comment: 28 pages, 11 figures, pdflatex. v2 minor typos correcte
Smooth tensionful higher-codimensional brane worlds with bulk and brane
  form fields

Completely regular tensionful codimension-n brane world solutions are
discussed, where the core of the brane is chosen to be a thin codimension-(n-1)
shell in an infinite volume flat bulk, and an Einstein-Hilbert term localized
on the brane is included (Dvali-Gabadadze-Porrati models). In order to support
such localized sources we enrich the vacuum structure of the brane by the
inclusion of localized form fields. We find that phenomenological constraints
on the size of the internal core seem to impose an upper bound to the brane
tension. Finite transverse-volume smooth solutions are also discussed.Comment: 1+14 pages, 2 figures; section 2.3 improved, typos corrected and
  references added. Published versio
Form factors of vector and axial-vector mesons in holographic D4-D8
  model

We calculate elastic and non-elastic electromagnetic form factors for vector
and axial-vector mesons in the holographic D4-D8 brane model. We obtain the
mass spectrum and Regge trajectories for these particles. From the elastic form
factors we extract the electric radius, the magnetic and quadrupole moments.
Form factors for transverse and longitudinal polarizations are also obtained.
We find superconvergence sum rules for the vector and axial-vector meson
couplings that determine the asymptotic behavior of the form factors at large
momentum transfer. Our results show good agreement with other holographic
models and QCD.Comment: 18 pages, 8 figures, 2 table
Vacuum Stability, Perturbativity, and Scalar Singlet Dark Matter

We analyze the one-loop vacuum stability and perturbativity bounds on a
singlet extension of the Standard Model (SM) scalar sector containing a scalar
dark matter candidate. We show that the presence of the singlet-doublet quartic
interaction relaxes the vacuum stability lower bound on the SM Higgs mass as a
function of the cutoff and lowers the corresponding upper bound based on
perturbativity considerations. We also find that vacuum stability requirements
may place a lower bound on the singlet dark matter mass for given singlet
quartic self coupling, leading to restrictions on the parameter space
consistent with the observed relic density. We argue that discovery of a light
singlet scalar dark matter particle could provide indirect information on the
singlet quartic self-coupling.Comment: 25 pages, 10 figures; v2 - fixed minor typos; v3 - added to text
  discussions of other references, changed coloring of figures for easier black
  and white viewin
Dimensionally regularized Polyakov loop correlators in hot QCD

A popular observable in finite-temperature lattice QCD is the so-called
singlet quark-antiquark free energy, conventionally defined in Coulomb gauge.
In an effort to interpret the existing numerical data on this observable, we
compute it at order O(alpha_s^2) in continuum, and analyze the result at
various distance scales. At short distances (r << 1/pi T) the behaviour matches
that of the gauge-independent zero-temperature potential; on the other hand at
large distances (r >> 1/pi T) the singlet free energy appears to have a
gauge-fixing related power-law tail. At infinite distance the result again
becomes physical in the sense that it goes over to a gauge-independent
disconnected contribution, the square of the expectation value of the trace of
the Polyakov loop; we recompute this quantity at O(alpha_s^2), finding for pure
SU(Nc) a different non-logarithmic term than in previous literature, and adding
for full QCD the quark contribution. We also discuss the value of the singlet
free energy in a general covariant gauge, as well as the behaviour of the
cyclic Wilson loop that is obtained if the singlet free energy is made
gauge-independent by inserting straight spacelike Wilson lines into the
observable. Comparisons with lattice data are carried out where possible.Comment: 38 pages. v2: reference added, published version. v3: erratum added
  for sec.5, main results unchange
Thermodynamics of Holographic Defects

Using the AdS/CFT correspondence, we study the thermodynamic properties and
the phase diagram of matter fields on (2+1)-dimensional defects coupled to a
(3+1)-dimensional N=4 SYM "heat bath". Considering a background magnetic field,
(net) quark density, defect "magnitude" $\delta N_c$ and the mass of the
matter, we study the defect contribution to the thermodynamic potentials and
their first and second derivatives to map the phases and study their physical
properties.
  We find some features that are qualitatively similar to other systems e.g. in
(3+1) dimensions and a number of features that are particular to the defect
nature, such as its magnetic properties, unexpected properties at T->0 and
finite density; and the finite $\delta N_c$ effects, e.g. a diverging
susceptibility and vanishing density of states at small temperatures, a
physically consistent negative heat capacity and new types of consistent
phases.Comment: 33 pages, 16 figures (jpg and pdf), typos fixed and references added,
  final version published in JHE
The RN/CFT Correspondence Revisited

We reconsidered the quantum gravity description of the near horizon extremal
Reissner-Nordstr{\o}m black hole in the viewpoint of the AdS$_2$/CFT$_1$
correspondence. We found that, for pure electric case, the right moving central
charge of dual 1D CFT is $6 Q^2$ which is different from the previous result $6
Q^3$ of left moving sector obtained by warped AdS$_3$/CFT$_2$ description. We
discussed the discrepancy in these two approaches and examined novel properties
of our result.Comment: revtex4, 16 pages, sign mistakes corrected, references include
Strong dark matter constraints on GMSB models

We reconsider the dark matter problem in supersymmetric models with gauge
mediated supersymmetry breaking, with and without R-parity breaking. In these
classes of models, a light gravitino forms the dark matter.Consistency with the
experimental data, in particular the dark matter abundance and the small-scale
power spectrum, requires additional entropy production after the decoupling of
the gravitino from the thermal bath. We demonstrate that the usual mechanism
via messenger number violating interactions does not work in models where the
messenger belongs to SU (5) representations. This is mainly a consequence of
two facts: (i) there are at least two different types of lightest messenger
particles and (ii) the lightest messenger particle with SU (2) quantum numbers
decays dominantly into vector bosons once messenger number is broken, a feature
which has been overlooked so far. In case of SO(10) messenger multiplets we
find scenarios which work if the SM gauge singlet component is rather light.Comment: 9 pages, 5 figure
Thermodynamics of SU(2) N=2 supersymmetric Yang-Mills theory

The thermodynamics of four-dimensional SU(2) N=2 super-Yang-Mills theory is
examined in both high and low temperature regimes. At low temperatures,
compelling evidence is found for two distinct equilibrium states related by a
spontaneously broken discrete R-symmetry. These equilibrium states exist
because the quantum moduli space of the theory has two singular points where
extra massless states appear. At high temperature, a unique
R-symmetry-preserving equilibrium state is found. Discrepancies with previous
results in the literature are explained.Comment: 41 pages, 6 figures; v2 added one footnote and three references,
  published versio
Radiative corrections to the neutral-current Drell-Yan process in the
  Standard Model and its minimal supersymmetric extension

An adequate description of the neutral-current Drell-Yan process at the
Tevatron and the LHC, in particular, requires the inclusion of electroweak
radiative corrections. We extend earlier work in this direction in various
ways. First, we define and numerically compare different methods to describe
the Z-boson resonance including next-to-leading order electroweak corrections;
moreover, we provide explicit analytical expressions for those. Second, we pay
particular attention to contributions from photon-photon and photon-quark
collisions, which involve photons in the initial state, and work out how their
impact can be enhanced by selection cuts. Third, we supplement the O(\alpha)
corrections by universal electroweak effects of higher order, such as universal
two-loop contributions from \Delta\alpha and \Delta\rho, and the leading
two-loop corrections in the high-energy Sudakov regime as well as multi-photon
radiation off muons in the structure-function approach. Finally, we present
results on the complete next-to-leading order electroweak and QCD corrections
within the minimal supersymmetric extension of the Standard Model.Comment: 57 pages, latex, 19 figures, 7 tables; photon PDF factorization
  changed; minor corrections; version to appear in JHE
F-theory and Neutrinos: Kaluza-Klein Dilution of Flavor Hierarchy

We study minimal implementations of Majorana and Dirac neutrino scenarios in F-theory GUT models. In both cases the mass scale of the neutrinos \(m_{\nu} \sim M_{weak}^2/\land_{UV}\) arises from integrating out Kaluza-Klein modes, where \(\land_{UV}\) is close to the GUT scale. The participation of non-holomorphic Kaluza-Klein mode wave functions dilutes the mass hierarchy in comparison to the quark and charged lepton sectors, in agreement with experimentally measured mass splittings. The neutrinos are predicted to exhibit a "normal" mass hierarchy, with masses \(m_3,m_2,m_1 \sim .05 \times (1,\alpha_{GUT}^{1/2},\alpha_{GUT}\)) eV. When the interactions of the neutrino and charged lepton sectors geometrically unify, the neutrino mixing matrix exhibits a mild hierarchical structure such that the mixing angles \(\theta_{23}\) and \(\theta_{12}\) are large and comparable, while \(\theta_{13}\) is expected to be smaller and close to the Cabibbo angle: \(\theta_{13} \sim \theta_{C} \sim \alpha_{GUT}^{1/2} \sim 0.2\). This suggests that \(\theta_{13}\) should be near the current experimental upper bound.Physic
D-brane orbiting NS5-branes

We study real time dynamics of a Dp-brane orbiting a stack of NS5-branes. It
is generally known that a BPS D-brane moving in the vicinity of NS5-branes
becomes unstable due to the presence of tachyonic degree of freedom induced on
the D-brane. Indeed, the D-brane necessarily falls into the fivebranes due to
gravitational attraction and eventually collapses into a pressureless fluid.
Such a decay of the D-brane is known to be closely related to the rolling
tachyon problem. In this paper we show that in special cases the decay of
D-brane caused by gravitational attraction can be avoided. Namely for certain
values of energy and angular momentum the D-brane orbits around the fivebranes,
maintaining certain distance from the fivebranes all the time, and the process
of tachyon condensation is suppressed. We show that the tachyonic degree of
freedom induced on such a D-brane really disappears and the brane returns to a
stable D-brane.Comment: 12 pages, latex, added referenc
DBI analysis of generalised permutation branes

We investigate D-branes on the product GxG of two group manifolds described
as Wess-Zumino-Novikov-Witten models. When the levels of the two groups
coincide, it is well known that there exist permutation D-branes which are
twisted by the automorphism exchanging the two factors. When the levels are
different, the D-brane charge group demands that there should be
generalisations of these permutation D-branes, and a geometric construction for
them was proposed in hep-th/0509153. We give further evidence for this proposal
by showing that the generalised permutation D-branes satisfy the
Dirac-Born-Infeld equations of motion for arbitrary compact, simply connected
and simple Lie groups G.Comment: 19 pages, computation in section 3.5.1 corrected, conclusions
  unchange
Non-perturbative computation of double inclusive gluon production in the
  Glasma

The near-side ridge observed in A+A collisions at RHIC has been described as
arising from the radial flow of Glasma flux tubes formed at very early times in
the collisions. We investigate the viability of this scenario by performing a
non-perturbative numerical computation of double inclusive gluon production in
the Glasma. Our results support the conjecture that the range of transverse
color screening of correlations determining the size of the flux tubes is a
semi-hard scale, albeit with non-trivial structure. We discuss our results in
the context of ridge correlations in the RHIC heavy ion experiments.Comment: 25 pages, 11 figures, uses JHEP3.cls V2: small clarifications,
  published in JHE
Partial breakdown of center symmetry in large-N QCD with adjoint Wilson
  fermions

We study the one-loop potential of large-N QCD with adjoint Dirac fermions.
Space-time is a discretization of R^3 x S^1 where the compact direction
consists of a single lattice site. We use Wilson fermions with different values
of the quark mass m and set the lattice spacings in the compact and non-compact
directions to be a_t and a_s respectively. Extending the results of JHEP
0906:091,2009, we prove that if the ratio xi = a_s/a_t obeys 0<xi<2, then the
minimum of the one-loop lattice potential for one or more Dirac flavors is Z_N
symmetric at the chiral point. For xi=0 our formulas reduce to those obtained
in a continuum regularization of the R^3, and our proof holds in that case as
well. As we increase m from zero, we find a cascade of transitions where Z_N
breaks to Z_K. For very small masses, K ~ 1/(a_t m) >> 1, while for large
masses K ~ O(1). Despite certain UV sensitivities of the lattice one-loop
potential, this phase structure is similar to the one obtained in the continuum
works of Kovtun-Unsal-Yaffe, Myers-Ogilvie, and Hollowood-Myers. We explain the
physical origin of the cascade of transitions and its relation to the embedding
of space-time into color space.Comment: 22 pages, 3 figures. V2: one typo corrected. published versio
Constraining sterile neutrinos with a low energy beta-beam

We show that a low energy beta-beam facility can be used to search for
sterile neutrinos by measuring the disappearance of electron anti-neutrinos.
This channel is particularly sensitive since it allows to use inverse beta
decay as detection reaction; thus it is free from hadronic uncertainties,
provided the neutrino energy is below the pion production threshold. This
corresponds to a choice of the Lorentz gamma=30 for the 6He parent ion.
Moreover, a disappearance measurement allows the constraint of sterile neutrino
properties independently of any CP violating effects. A moderate detector size
of a few 100 tons and ion production rates of 2E13 per second are sufficient to
constrain mixing angles as small as \sin^22\theta=0.01 at 99% confidence level.Comment: 12 pages, 5 figures. Minor clarifications and few references added.
  Accepted in JHE