pinecone/core-2020-05-10-deduplication huggingface dataset:
The Sphaleron Rate in SU(N) Gauge Theory

The sphaleron rate is defined as the diffusion constant for topological
number NCS = int g^2 F Fdual/32 pi^2. It establishes the rate of equilibration
of axial light quark number in QCD and is of interest both in electroweak
baryogenesis and possibly in heavy ion collisions. We calculate the
weak-coupling behavior of the SU(3) sphaleron rate, as well as making the most
sensible extrapolation towards intermediate coupling which we can. We also
study the behavior of the sphaleron rate at weak coupling at large Nc.Comment: 18 pages with 3 figure
A projective Dirac operator on CP^2 within fuzzy geometry

We propose an ansatz for the commutative canonical spin_c Dirac operator on
CP^2 in a global geometric approach using the right invariant (left action-)
induced vector fields from SU(3). This ansatz is suitable for noncommutative
generalisation within the framework of fuzzy geometry. Along the way we
identify the physical spinors and construct the canonical spin_c bundle in this
formulation. The chirality operator is also given in two equivalent forms.
Finally, using representation theory we obtain the eigenspinors and calculate
the full spectrum. We use an argument from the fuzzy complex projective space
CP^2_F based on the fuzzy analogue of the unprojected spin_c bundle to show
that our commutative projected spin_c bundle has the correct
SU(3)-representation content.Comment: reduced to 27 pages, minor corrections, minor improvements, typos
  correcte
Yukawa couplings and fermion mass structure in F-theory GUTs

The calculation of Yukawa couplings in F-theory GUTs is developed. The method
is applied to the top and bottom Yukawa couplings in an SU(5) model of fermion
masses based on family symmetries coming from the SU(5)_\perp factor in the
underlying E(8) theory. The remaining Yukawa couplings involving the light
quark generations are determined by the Froggatt Nielsen non-renormalisable
terms generated by heavy messenger states. We extend the calculation of Yukawa
couplings to include massive states and estimate the full up and down quark
mass matrices in the SU(5) model. We discuss the new features of the resulting
structure compared to what is usually assumed for Abelian family symmetry
models and show how the model can give a realistic quark mass matrix structure.
We extend the analysis to the neutrino sector masses and mixing where we find
that tri-bi-maximal mixing is readily accommodated. Finally we discuss
mechanisms for splitting the degeneracy between the charged leptons and the
down quarks and the doublet triplet splitting in the Higgs sector.Comment: 32 page
Holographic Anomalous Conductivities and the Chiral Magnetic Effect

We calculate anomaly induced conductivities from a holographic gauge theory
model using Kubo formulas, making a clear conceptual distinction between
thermodynamic state variables such as chemical potentials and external
background fields. This allows us to pinpoint ambiguities in previous
holographic calculations of the chiral magnetic conductivity. We also calculate
the corresponding anomalous current three-point functions in special kinematic
regimes. We compare the holographic results to weak coupling calculations using
both dimensional regularization and cutoff regularization. In order to
reproduce the weak coupling results it is necessary to allow for singular
holographic gauge field configurations when a chiral chemical potential is
introduced for a chiral charge defined through a gauge invariant but
non-conserved chiral density. We argue that this is appropriate for actually
addressing charge separation due to the chiral magnetic effect.Comment: 17 pages, 1 figure. v2: 18 pages, 1 figure, discussion clarified
  throughout the text, references added, version accepted for publication in
  JHE
Quantum Corrections to Heterotic Moduli Potentials

In a recent paper, we derived the leading alpha' corrections to the Kahler
potentials for moduli in (0,2) heterotic compactifications. In the same spirit
as the LARGE volume stabilization scenario for type IIB orientifolds, we
examine whether these quantum corrections, together with a combination of
tree-level and non-perturbative superpotentials, are sufficient to stabilize
the overall volume modulus at large values. This is not a priori obvious, since
the corrections we found are of a lower order than those used in the type IIB
setting. Nevertheless, we find that stabilizing the volume at (exponentially)
large values may be possible (under certain conditions) in these heterotic
backgrounds.Comment: 27+1 pages, LaTeX; minor corrections, references added; new section
  adde
D=7 / D=6 Heterotic Supergravity with Gauged R-Symmetry

We construct a family of chiral anomaly-free supergravity theories in D=6
starting from D=7 supergravity with a gauged noncompact R-symmetry, employing a
Horava-Witten bulk-plus-boundary construction. The gauged noncompact R-symmetry
yields a positive (de Sitter sign) D=6 scalar field potential. Classical
anomaly inflow which is needed to cancel boundary-field loop anomalies requires
careful consideration of the gravitational, gauge, mixed and local
supersymmetry anomalies. Coupling of boundary hypermultiplets requires care
with the Sp(1) gauge connection required to obtain quaternionic Kahler target
manifolds in D=6. This class of gauged R-symmetry models may be of use as
starting points for further compactifications to D=4 that take advantage of the
positive scalar potential, such as those proposed in the scenario of
supersymmetry in large extra dimensions.Comment: 43 pages, plain Latex; Clarification of discussion and references
  adde
On All-loop Integrands of Scattering Amplitudes in Planar N=4 SYM

We study the relationship between the momentum twistor MHV vertex expansion
of planar amplitudes in N=4 super-Yang-Mills and the all-loop generalization of
the BCFW recursion relations. We demonstrate explicitly in several examples
that the MHV vertex expressions for tree-level amplitudes and loop integrands
satisfy the recursion relations. Furthermore, we introduce a rewriting of the
MHV expansion in terms of sums over non-crossing partitions and show that this
cyclically invariant formula satisfies the recursion relations for all numbers
of legs and all loop orders.Comment: 34 pages, 17 figures; v2: Minor improvements to exposition and
  discussion, updated references, typos fixe
T-functions and multi-gluon scattering amplitudes

We study gluon scattering amplitudes/Wilson loops in =4 super Yang-Mills theory at strong coupling which correspond to minimal surfaces with a light-like polygonal boundary in AdS3. We find a concise expression of the remainder function in terms of the T-function of the associated thermodynamic Bethe ansatz (TBA) system. Continuing our previous work on the analytic expansion around the CFT/regular-polygonal limit, we derive a formula of the leading-order expansion for the general 2n-point remainder function. The T-system allows us to encode its momentum dependence in only one function of the TBA mass parameters, which is obtained by conformal perturbation theory. We compute its explicit form in the single mass cases. We also find that the rescaled remainder functions at strong coupling and at two loops are close to each other, and their ratio at the leading order approaches a constant near 0.9 for large n
Two-loop QCD helicity amplitudes for $ q\overline q $ → W ±γ and $ q\overline q $ → Z 0γ

The self-couplings of the electroweak gauge bosons are probed at hadron colliders through the production of a massive gauge boson and a photon. To extend the theoretical description of this type of final states towards next-to-next-to-leading order (NNLO) in QCD, we derive the two-loop QCD corrections to the helicity amplitudes describing the production of a massive gauge boson in association with a real photon. Our results are obtained by applying projectors to the general parton-level tensor structure. The leptonic decay of the vector boson is included, thus allowing for a fully exclusive description of the final state. The infrared poles of the amplitudes are described by an infrared factorization formula. We provide an analytic expression for the finite remainder of the amplitude in terms of one- and two-dimensional harmonic polylogarithms. The amplitudes are expressed in the physical kinematics relevant to gauge-boson-plus-photon production at hadron colliders. As a by-product, we also derive the two-loop QCD amplitudes for vector-boson-plus-jet production at hadron colliders
N=1 SQCD and the Transverse Field Ising Model

We study the dimensions of non-chiral operators in the Veneziano limit of N=1
supersymmetric QCD in the conformal window. We show that when acting on
gauge-invariant operators built out of scalars, the 1-loop dilatation operator
is equivalent to the spin chain Hamiltonian of the 1D Ising model in a
transverse magnetic field, which is a nontrivial integrable system that is
exactly solvable at finite length. Solutions with periodic boundary conditions
give the anomalous dimensions of flavor-singlet operators and solutions with
fixed boundary conditions give the anomalous dimensions of operators whose ends
contain open flavor indices.Comment: 17 pages, 2 figure
On Flux Quantization in F-Theory

We study the problem of four-form flux quantization in F-theory
compactifications. We prove that for smooth, elliptically fibered Calabi-Yau
fourfolds with a Weierstrass representation, the flux is always integrally
quantized. This implies that any possible half-integral quantization effects
must come from 7-branes, i.e. from singularities of the fourfold. We
subsequently analyze the quantization rule on explicit fourfolds with Sp(N)
singularities, and connect our findings via Sen's limit to IIB string theory.
Via direct computations we find that the four-form is half-integrally quantized
whenever the corresponding 7-brane stacks wrap non-spin complex surfaces, in
accordance with the perturbative Freed-Witten anomaly. Our calculations on the
fourfolds are done via toric techniques, whereas in IIB we rely on Sen's
tachyon condensation picture to treat bound states of branes. Finally, we give
general formulae for the curvature- and flux-induced D3 tadpoles for general
fourfolds with Sp(N) singularities.Comment: 46 page
Systematic analysis of the B-s -> f(0)l(+)l(-) in the universal extra dimension

Using form factors enrolled to the transition matrix elements and calculated via light-cone QCD sum rules including next-to-leading order corrections in the strong coupling constant, we provide a systematic analysis of the Bs -> f(0)(980)l(+)l(-) both in the standard and universal extra dimension models. In particular, we discuss sensitivity of the differential branching ratio and various double lepton polarization asymmetries on the compactification factor of extra dimension and show how the results of the extra dimension model deviate from the standard model predictions. The order of branching ratio makes this decay mode possible to be checked at LHCb in near future
Supersymmetric States in Large N Chern-Simons-Matter Theories

In this paper we study the spectrum of BPS operators/states in N=2
superconformal U(N) Chern-Simons-matter theories with adjoint chiral matter
fields, with and without superpotential. The superconformal indices and
conjectures on the full supersymmetric spectrum of the theories in the large N
limit with up to two adjoint matter fields are presented. Our results suggest
that some of these theories may have supergravity duals at strong coupling,
while some others may be dual to higher spin theories of gravity at strong
coupling. For the N=2 theory with no superpotential, we study the
renormalization of R-charge at finite 't Hooft coupling using "Z-minimization".
A particularly intriguing result is found in the case of one adjoint matter.Comment: 53 pages, 18 figures. v2: improved numerics, additional comments
  adde
(Anti-)brane backreaction beyond perturbation theory

We improve on the understanding of the backreaction of anti-D6-branes in a ux background that is mutually BPS with D6-branes. This setup is analogous to the study of the backreaction of anti-D3-branes inserted in the KS throat, but does not require us to smear the anti-branes or do a perturbative analysis around the BPS background. We solve the full equations of motion near the anti-D6-branes and show that only two boundary conditions are consistent with the equations of motion. Upon invoking a topological argument we eliminate the boundary condition with regular H ux since it cannot lead to a solution that approaches the right kind of ux away from the anti-D6-branes. This leaves us with a boundary condition which has singular, but integrable, H ux energy density
Future Boundary Conditions in de Sitter Space

We consider asymptotically future de Sitter spacetimes endowed with an eternal observatory. In the conventional descriptions, the conformal metric at the future boundary \(I^+\) is deformed by the flux of gravitational radiation. We however impose an unconventional future “Dirichlet” boundary condition requiring that the conformal metric is flat everywhere except at the conformal point where the observatory arrives at \(I^+\). This boundary condition violates conventional causality, but we argue the causality violations cannot be detected by any experiment in the observatory. We show that the bulk-to-bulk two-point functions obeying this future boundary condition are not realizable as operator correlation functions in any normalizable de Sitter invariant vacuum, but they do agree with those obtained by double analytic continuation from anti-de Sitter space.Physic
Double quiver gauge theory and nearly Kahler flux compactifications

We consider G-equivariant dimensional reduction of Yang-Mills theory with
torsion on manifolds of the form MxG/H where M is a smooth manifold, and G/H is
a compact six-dimensional homogeneous space provided with a never integrable
almost complex structure and a family of SU(3)-structures which includes a
nearly Kahler structure. We establish an equivalence between G-equivariant
pseudo-holomorphic vector bundles on MxG/H and new quiver bundles on M
associated to the double of a quiver Q, determined by the SU(3)-structure, with
relations ensuring the absence of oriented cycles in Q. When M=R^2, we describe
an equivalence between G-invariant solutions of Spin(7)-instanton equations on
MxG/H and solutions of new quiver vortex equations on M. It is shown that
generic invariant Spin(7)-instanton configurations correspond to quivers Q that
contain non-trivial oriented cycles.Comment: 42 pages; v2: minor corrections; Final version to be published in
  JHE
Colored Scalars And The CDF $W+$dijet Excess

The recent data on $W+$dijet excess reported by CDF may be interpreted as the
associated production of a $W$ and a new particle of mass about 150 GeV which
subsequently decays into two hadron jets. We study the possibility of
explaining the $W+$dijet excess by colored scalar bosons. There are several
colored scalars which can have tree level renormalizable Yukawa couplings with
two quarks, $({\bf 8}, {\bf 2},1/2)$, $(\bar{\bf 6}({\bf 3}), {\bf 3}({\bf 1}),
-1/3)$, $(\bar {\bf 6}({\bf 3}), {\bf 1}, -4/3(2/3))$. If one of these scalars
has a mass about 150 GeV, being colored it can naturally explain why the excess
only shows up in the form of two hadron jets. Although the required production
cross section and mass put constraints on model parameters and rule out some
possible scenarios when confronted with other existing data, in particular FCNC
data, we find that there are strong constraints on the Yukawa couplings of
these scalars. Without forcing the couplings to be some special texture forms
most of the scalars, except the $({\bf 3}, {\bf 3}, -1/3)$, are in trouble with
FCNC data. We also study some features for search of these new particles at the
RHIC and the LHC and find that related information can help further to
distinguish different models.Comment: RevTex, 17 pages and 4 figures. Some minor correction
Hefty MSSM-like light Higgs in extended gauge models

It is well known that in the MSSM the lightest neutral Higgs h^0 must be, at the tree level, lighter than the Z boson and that the loop corrections shift this stringent upper bound up to about 130 GeV. Extending the MSSM gauge group in a suitable way, the new Higgs sector dynamics can push the tree-level mass of h^0 well above the tree-level MSSM limit if it couples to the new gauge sector. This effect is further pronounced at the loop level and h^0 masses in the 140 GeV ballpark can be reached easily. We exemplify this for a sample setting with a low-scale U(1)_R x U(1)_B-L gauge symmetry in which neutrino masses can be implemented via the inverse seesaw mechanism
BKM Lie superalgebra for the Z_5 orbifolded CHL string

We study the Z_5-orbifolding of the CHL string theory by explicitly
constructing the modular form tilde{Phi}_2 generating the degeneracies of the
1/4-BPS states in the theory. Since the additive seed for the sum form is a
weak Jacobi form in this case, a mismatch is found between the modular forms
generated from the additive lift and the product form derived from threshold
corrections. We also construct the BKM Lie superalgebra, tilde{G}_5,
corresponding to the modular form tilde{Delta}_1 (Z) = tilde{Phi}_2 (Z)^{1/2}
which happens to be a hyperbolic algebra. This is the first occurrence of a
hyperbolic BKM Lie superalgebra. We also study the walls of marginal stability
of this theory in detail, and extend the arithmetic structure found by Cheng
and Dabholkar for the N=1,2,3 orbifoldings to the N=4,5 and 6 models, all of
which have an infinite number of walls in the fundamental domain. We find that
analogous to the Stern-Brocot tree, which generated the intercepts of the walls
on the real line, the intercepts for the N >3 cases are generated by linear
recurrence relations. Using the correspondence between the walls of marginal
stability and the walls of the Weyl chamber of the corresponding BKM Lie
superalgebra, we propose the Cartan matrices for the BKM Lie superalgebras
corresponding to the N=5 and 6 models.Comment: 30 pages, 2 figure
Four-lepton production at hadron colliders: aMC@NLO predictions with theoretical uncertainties

We use aMC@NLO to study the production of four charged leptons at the LHC, performing parton showers with both HERWIG and P ythia6. Our underlying matrix element calculation features the full next-to-leading order mathcal{O}left( {{α_s}} right) result and the mathcal{O}left( {α_s^2} right) contribution of the gg channel, and it includes all off-shell, spin-correlation, virtual-photon-exchange, and interference effects. We present several key distributions together with the corresponding theoretical uncertainties. These are obtained through a process-independent technique that allows aMC@NLO to compute scale and PDF uncertainties in a fully automated way and at no extra CPU-time cost
Higgs Production via Weak Boson Fusion in the Standard Model and the
  MSSM

Weak boson fusion is expected to be an important Higgs production channel at
the LHC. Complete one-loop results for weak boson fusion in the Standard Model
have been obtained by calculating the full virtual electroweak corrections and
photon radiation and implementing these results into the public Monte Carlo
program VBFNLO which includes the NLO QCD corrections. Furthermore the dominant
supersymmetric one-loop corrections to neutral Higgs production, in the general
case where the MSSM includes complex phases, have been calculated. These
results have been combined with all one-loop corrections of Standard Model type
and with the propagator-type corrections from the Higgs sector of the MSSM up
to the two-loop level. Within the Standard Model the electroweak corrections
are found to be as important as the QCD corrections after the application of
appropriate cuts. The corrections yield a shift in the cross section of order
5% for a Higgs of mass 100-200 GeV, confirming the result obtained previously
in the literature. For the production of a light Higgs boson in the MSSM the
Standard Model result is recovered in the decoupling limit, while the loop
contributions from superpartners to the production of neutral MSSM Higgs bosons
can give rise to corrections in excess of 10% away from the decoupling region.Comment: 33 pages, 10 figures, and 2 tables. Version accepted by JHE
Yang-Mills fields in flux compactifications on homogeneous manifolds
  with SU(4)-structure

The SU(4)-instanton equations are natural BPS equations for instantons on
8-manifolds. We study these equations on nearly Kaehler and Calabi-Yau torsion
manifolds of the form M x G/H, with G/H a coset space and M a product of a
torus with Euclidean space. By imposing G-invariance the instanton equations
reduce to interesting equations on M; for example, equations used by Kapustin
and Witten in the geometric Langlands program arise in this way. We carry out
reductions in a number of examples, and where possible present simple
solutions.Comment: 28+1 pages, 1 figure. v2 (published version) minor corrections to
  formulae and tex
Supersymmetric mass spectra and the seesaw type-I scale

We calculate supersymmetric mass spectra with cMSSM boundary conditions and a type-I seesaw mechanism added to explain current neutrino data. Using published, estimated errors on SUSY mass observables for a combined LHC+ILC analysis, we perform a theoretical chi(2) analysis to identify parameter regions where pure cMSSM and cMSSM plus seesaw type-I might be distinguishable with LHC+ILC data. The most important observables are determined to be the (left) smuon and selectron masses and the splitting between them, respectively. Splitting in the (left) smuon and selectrons is tiny in most of cMSSM parameter space, but can be quite sizeable for large values of the seesaw scale, m S S. Thus, for very roughly m(SS) >= 10(14) GeV hints for type-I seesaw might appear in SUSY mass measurements. Since our numerical results depend sensitively on forecasted error bars, we discuss in some detail the accuracies, which need to be achieved, before a realistic analysis searching for signs of type-I seesaw in SUSY spectra can be carried out
New instability of non-extremal black holes: spitting out supertubes

We search for stable bound states of non-extremal rotating three-charge black holes in five dimensions (Cvetic-Youm black holes) and supertubes. We do this by studying the potential of supertube probes in the non-extremal black hole background and find that generically the marginally bound state of the supersymmetric limit becomes metastable and disappears with non-extremality (higher temperature). However near extremality there is a range of parameters allowing for stable bound states, which have lower energy than the supertube-black hole merger. Angular momentum is crucial for this effect. We use this setup in the D1-D5 decoupling limit to map a thermodynamic instability of the CFT (a new phase which is entropically dominant over the black hole phase) to a tunneling instability of the black hole towards the supertube-black hole bound state. This generalizes the results of ArXiv:1108.0411 [hep-th], which mapped an entropy enigma in the bulk to the dual CFT in a supersymmetric setup.status: publishe
Dangerous skyrmions in little Higgs models

Skyrmions are present in many models of electroweak symmetry breaking where the Higgs is a pseudo-oldstone boson of some strongly interacting sector. They are stable, composite objects whose mass lies in the range 10-100 TeV and can be naturally abundant in the universe due to their small annihilation cross-section. They represent therefore good dark matter candidates. We show however in this work that the lightest skyrmion states are electrically charged in most of the popular little Higgs models, and hence should have been directly or indirectly observed in nature already. The charge of the skyrmion under the electroweak gauge group is computed in a model-independent way and is related to the presence of anomalies in the underlying theory via the Wess-Zumino-Witten term