pinecone/core-2020-05-10-deduplication huggingface dataset:
On the energy dependence of the dipole-proton cross section in deep inelastic scattering

We study the dipole picture of high-energy virtual-photon-proton scattering. It is shown that different choices for the energy variable in the dipole cross section used in the literature are not related to each other by simple arguments equating the typical dipole size and the inverse photon virtuality, contrary to what is often stated. We argue that the good quality of fits to structure functions that use Bjorken- x as the energy variable — which is strictly speaking not justified in the dipole picture — can instead be understood as a consequence of the sign of scaling violations that occur for increasing Q 2 at fixed small x. We show that the dipole formula for massless quarks has the structure of a convolution. From this we obtain derivative relations between the structure function F 2 at large and small Q 2 and the dipole-proton cross section at small and large dipole size r, respectively
Accelerated detectors and worldsheet horizons in AdS/CFT

We use the AdS/CFT correspondence to discuss the response of an accelerated
observer to the quantum vacuum fluctuations. In particular, we study heavy
quarks probing a strongly coupled CFT by analysing strings moving in AdS. We
propose that, in this context, a non-trivial detection rate is associated to
the existence of a worldsheet horizon and we find an Unruh-like expression for
the worldsheet temperature. Finally, by examining a rotating string in global
AdS we find that there is a transition between string embeddings with and
without worldsheet horizon. The dual picture corresponds to having non-trivial
or trivial interaction with the quantum vacuum respectively. This is in
qualitative agreement with results of Davies et al.Comment: 34 pages, 2 figures; references added, discussion improve
Random matrix theory of unquenched two-colour QCD with nonzero chemical
  potential

We solve a random two-matrix model with two real asymmetric matrices whose
primary purpose is to describe certain aspects of quantum chromodynamics with
two colours and dynamical fermions at nonzero quark chemical potential mu. In
this symmetry class the determinant of the Dirac operator is real but not
necessarily positive. Despite this sign problem the unquenched matrix model
remains completely solvable and provides detailed predictions for the Dirac
operator spectrum in two different physical scenarios/limits: (i) the
epsilon-regime of chiral perturbation theory at small mu, where mu^2 multiplied
by the volume remains fixed in the infinite-volume limit and (ii) the
high-density regime where a BCS gap is formed and mu is unscaled. We give
explicit examples for the complex, real, and imaginary eigenvalue densities
including Nf=2 non-degenerate flavours. Whilst the limit of two degenerate
masses has no sign problem and can be tested with standard lattice techniques,
we analyse the severity of the sign problem for non-degenerate masses as a
function of the mass split and of mu.
  On the mathematical side our new results include an analytical formula for
the spectral density of real Wishart eigenvalues in the limit (i) of weak
non-Hermiticity, thus completing the previous solution of the corresponding
quenched model of two real asymmetric Wishart matrices.Comment: 45 pages, 31 figures; references added, as published in JHE
Relic densities including Sommerfeld enhancements in the MSSM

We have developed a general formalism to compute Sommerfeld enhancement (SE)
factors for a multi-state system of fermions, in all possible spin
configurations and with generic long-range interactions. We show how to include
such SE effects in an accurate calculation of the thermal relic density for
WIMP dark matter candidates. We apply the method to the MSSM and perform a
numerical study of the relic abundance of neutralinos with arbitrary
composition and including the SE due to the exchange of the W and Z bosons,
photons and Higgses. We find that the relic density can be suppressed by a
factor of a few in a seizable region of the parameter space, mostly for
Wino-like neutralino with mass of a few TeV, and up to an order of magnitude
close to a resonance.Comment: 23 pages, 7 figures; table 1 corrected and rearranged, numerical
  results practically unchanged, matches published versio
Supersymmetric Charged Clouds in AdS_5

We consider supersymmetric holographic flows that involve background gauge
fields dual to chemical potentials in the boundary field theory. We use a
consistent truncation of gauged N=8 supergravity in five dimensions and we give
a complete analysis of the supersymmetry conditions for a large family of
flows. We examine how the well-known supersymmetric flow between two fixed
points is modified by the presence of the chemical potentials and this yields a
new, completely smooth, solution that interpolates between two global AdS
spaces of different radii and with different values of the chemical potential.
We also examine some black-hole-like singular flows and a new
non-supersymmetric black hole solution. We comment on the interpretation of our
new solutions in terms of giant gravitons and discuss the implications of our
work for finding black-hole solutions in AdS geometries.Comment: 31 pages, 6 figures; minor corrections, updated reference
Constraints for the nuclear parton distributions from Z and W production
  at the LHC

The LHC is foreseen to finally bring also the nuclear collisions to the TeV
scale thereby providing new possibilities for physics studies, in particular
related to the electro-weak sector of the Standard Model. We study here the Z
and W production in proton-lead and lead-lead collisions at the LHC,
concentrating on the prospects of testing the factorization and constraining
the nuclear modifications of the parton distribution functions (PDFs).
Especially, we find that the rapidity asymmetries in proton-nucleus collisions,
arising from the differences in the PDFs between the colliding objects, provide
a decisive advantage in comparison to the rapidity-symmetric nucleus-nucleus
case. We comment on how such studies will help to improve our knowledge of the
nuclear PDFs.Comment: The version accepted for publication in JHEP. New figures has been
  added, and we also discuss the single charged lepton productio
T-parity, its problems and their solution

We point out a basic difficulty in the construction of little-Higgs models
with T-parity which is overlooked by large part of the present literature.
Almost all models proposed so far fail to achieve their goal: they either
suffer from sizable electroweak corrections or from a breakdown of collective
breaking. We provide a model building recipe to bypass the above problem and
apply it to build the simplest T-invariant extension of the Littlest Higgs. Our
model predicts additional T-odd pseudo-Goldstone bosons with weak scale masses.Comment: 25 pages, 2 appendice
Quasi-normal frequencies: Key analytic results

The study of exact quasi-normal modes [QNMs], and their associated
quasi-normal frequencies [QNFs], has had a long and convoluted history -
replete with many rediscoveries of previously known results. In this article we
shall collect and survey a number of known analytic results, and develop
several new analytic results - specifically we shall provide several new QNF
results and estimates, in a form amenable for comparison with the extant
literature. Apart from their intrinsic interest, these exact and approximate
results serve as a backdrop and a consistency check on ongoing efforts to find
general model-independent estimates for QNFs, and general model-independent
bounds on transmission probabilities. Our calculations also provide yet another
physics application of the Lambert W function. These ideas have relevance to
fields as diverse as black hole physics, (where they are related to the damped
oscillations of astrophysical black holes, to greybody factors for the Hawking
radiation, and to more speculative state-counting models for the Bekenstein
entropy), to quantum field theory (where they are related to Casimir energies
in unbounded systems), through to condensed matter physics, (where one may
literally be interested in an electron tunelling through a physical barrier).Comment: V1: 29 pages; V2: Reformatted, 31 pages. Title changed to reflect
  major additions and revisions. Now describes exact QNFs for the double-delta
  potential in terms of the Lambert W function. V3: Minor edits for clarity.
  Four references added. No physics changes. Still 31 page
Semi-direct Gauge-Yukawa Mediation

We propose semi-direct Gauge-Yukawa mediation of supersymmetry (SUSY)
breaking. The messenger fields mediating SUSY breaking to the visible sector do
not directly couple with the goldstino field, and instead they have gauge and
Yukawa interactions with some primary messenger fields which couple directly
with the goldstino fields. From the explicit Feynman diagram calculations for
the SUSY breaking soft masses, we find that the SUSY particle spectra can be
realistic. Especially, this generalization of semi-direct gauge mediation
solves the massless gaugino mass problem since the holomorphic soft mass terms
of the messenger fields can be generated by Yukawa couplings. We also provide
some arguments that this scenario can be realized naturally in some dynamical
SUSY-breaking models such as the ISS-like model.Comment: comments and refs adde
Democratic Superstring Field Theory: Gauge Fixing

We show that a partial gauge fixing of the NS sector of the
democratic-picture superstring field theory leads to the non-polynomial theory.
Moreover, by partially gauge fixing the Ramond sector we obtain a
non-polynomial fully RNS theory at pictures 0 and 1/2. Within the democratic
theory and in the partially gauge fixed theory the equations of motion of both
sectors are derived from an action. We also discuss a representation of the
non-polynomial theory analogous to a manifestly two-dimensional representation
of WZW theory and the action of bosonic pure-gauge solutions.
  We further demonstrate that one can consistently gauge fix the NS sector of
the democratic theory at picture number -1. The resulting theory is new. It is
a Z_2 dual of the modified cubic theory. We construct analytical solutions of
this theory and show that they possess the desired properties.Comment: V1: 33p. V2: Added 3.3.2, with a fully RNS action at pictures 0 and
  1/2, typos corrected, 36p. V3: Presentation improved in 2.1, 3.1 and
  elsewhere, ref. added, 37p. V4: Footnote 6 modified, typos corrected, 37
Open mirror symmetry for Pfaffian Calabi-Yau 3-folds

We investigate the open mirror symmetry of certain non-complete intersection
Calabi- Yau 3-folds, so called pfaffian Calabi-Yau. We perform the prediction
of the number of disk invariants of several examples by using the direct
integration method proposed recently and the open mirror symmetry. We treat
several pfaffian Calabi-Yau 3-folds in $\mathbb{P}^6$ and branes with two
discrete vacua. Some models have the two special points in its moduli space,
around both of which we can consider different A-model mirror partners. We
compute disc invariants for both cases. This study is the first application of
the open mirror symmetry to the compact non-complete intersections in toric
variety.Comment: 64 pages; v2: typos corrected, minor changes, references added; v3:
  published version, minor corrections and improvement
Origins of Hidden Sector Dark Matter II: Collider Physics

We consider a broad class of supersymmetric theories in which dark matter
(DM) is the lightest superpartner (LSP) of a hidden sector that couples very
weakly to visible sector fields. Portal interactions connecting visible and
hidden sectors mediate the decay of the lightest observable superpartner (LOSP)
into the LSP, allowing the LHC to function as a spectacular probe of the origin
of hidden sector DM. As shown in a companion paper, this general two-sector
framework allows only for a handful of DM production mechanisms, each of which
maps to a distinctive window in lifetimes and cross-sections for the LOSP. In
the present work we perform a systematic collider study of LOSP candidates and
portal interactions, and for each case evaluate the prospects for successfully
reconstructing the origin of DM at the LHC. If, for instance, DM arises from
Freeze-Out and Decay, this may be verified if the LOSP is a bino or
right-handed slepton decaying to the LSP through a variety of portal
interactions, and with an annihilation cross-section within a narrow range. On
the other hand, the Freeze-In mechanism may be verified for a complimentary set
of LOSP candidates, and within a narrow range of LOSP lifetimes. In all cases,
the LOSP is relatively long-lived on collider time scales, leading to events
with displaced vertices. Furthermore, scenarios with a charged or colored LOSP
are particularly promising.Comment: 34 pages, 4 figure
Reconstructing f(R) modified gravity from ordinary and entropy-corrected
  versions of the holographic and new agegraphic dark energy models

Here, we peruse cosmological usage of the most promising candidates of dark
energy in the framework of f(R) theory. We reconstruct the different f(R)
modified gravity models in the spatially flat FRW universe according to the
ordinary and entropy-corrected versions of the holographic and new agegraphic
dark energy models, which describe accelerated expansion of the universe. We
also obtain the equation of state parameter of the corresponding f(R)-gravity
models. We conclude that the holographic and new agegraphic f(R)-gravity models
can behave like phantom or quintessence models. Whereas the equation of state
parameter of the entropy-corrected models can transit from quintessence state
to phantom regime as indicated by recent observations.Comment: 17 pages, accepted for publication in JHE
A simple collinear limit of scattering amplitudes at strong coupling

Collinear limit usually provides strong constraints for scattering
amplitudes. At strong coupling, collinear limit of the amplitudes in N=4 SYM is
related to the large mass limit of the corresponding Y system. In this paper,
we consider a special case in which all mass parameters are taken to be large,
which corresponds to a multi-double-collinear limit in which a n-side polygon
becomes pentagons. This limit provides a useful constraint for amplitudes, in
particular, can be used to fix the periods part for the case of 4K gluons,
which is the last missing piece of full amplitudes.Comment: v3: 22 pages, comments and a new subsection 5.1 added, typos fixe
The effects of minimal length and maximal momentum on the transition
  rate of ultra cold neutrons in gravitational field

The existence of a minimum observable length and/or a maximum observable
momentum is in agreement with various candidates of quantum gravity such as
string theory, loop quantum gravity, doubly special relativity and black hole
physics. In this scenario, the Heisenberg uncertainty principle is changed to
the so-called Generalized (Gravitational) Uncertainty Principle (GUP) which
results in modification of all Hamiltonians in quantum mechanics. In this
paper, following a recently proposed GUP which is consistent with quantum
gravity theories, we study the quantum mechanical systems in the presence of
both a minimum length and a maximum momentum. The generalized Hamiltonian
contains two additional terms which are proportional to $\alpha p^3$ and
$\alpha^2 p^4$ where $\alpha \sim 1/M_{Pl}c$ is the GUP parameter. For the case
of a quantum bouncer, we solve the generalized Schrodinger equation in the
momentum space and find the modified energy eigenvalues and eigenfunctions up
to the second-order in GUP parameter. The effects of the GUP on the transition
rate of ultra cold neutrons in gravitational spectrometers are discussed
finally.Comment: 13 pages, 1 figure, to appear in JHE
Dimensional reduction of the ABJM model

We dimensionally reduce the ABJM model, obtaining a two-dimensional theory
that can be thought of as a 'master action'. This encodes information about
both T- and S-duality, i.e. describes fundamental (F1) and D-strings (D1) in 9
and 10 dimensions. The Higgsed theory at large VEV and large k yields D1-brane
actions in 9d and 10d, depending on which auxiliary fields are integrated out.
For N=1 there is a map to a Green-Schwarz string wrapping a nontrivial circle
in C^4/Z_k.Comment: 23 pages, Latex; v2: added some clarifying comments on the action of
  T-duality in Section 2.1.
Ground States of S-duality Twisted N=4 Super Yang-Mills Theory

We study the low-energy limit of a compactification of N=4 U(n) super
Yang-Mills theory on $S^1$ with boundary conditions modified by an S-duality
and R-symmetry twist. This theory has N=6 supersymmetry in 2+1D. We analyze the
$T^2$ compactification of this 2+1D theory by identifying a dual weakly coupled
type-IIA background. The Hilbert space of normalizable ground states is
finite-dimensional and appears to exhibit a rich structure of sectors. We
identify most of them with Hilbert spaces of Chern-Simons theory (with
appropriate gauge groups and levels). We also discuss a realization of a
related twisted compactification in terms of the (2,0)-theory, where the recent
solution by Gaiotto and Witten of the boundary conditions describing D3-branes
ending on a (p,q) 5-brane plays a crucial role.Comment: 104 pages, 5 figures. Revisions to subsection (6.6) and other minor
  corrections included in version
Search for electromagnetic properties of the neutrinos at the LHC

Exclusive production of neutrinos via photon-photon fusion provides an
excellent opportunity to probe electromagnetic properties of the neutrinos at
the LHC. We explore the potential of processes pp-> p gamma gamma p -> p nu
anti-nu p and pp -> p gamma gamma p -> p nu anti-nu Z p to probe
neutrino-photon and neutrino-two photon couplings. We show that these reactions
provide more than seven orders of magnitude improvement in neutrino-two photon
couplings compared to LEP limits.Comment: 11 pages, 4 tables, New backgrounds have been adde
Brezin-Gross-Witten model as "pure gauge" limit of Selberg integrals

The AGT relation identifies the Nekrasov functions for various N=2 SUSY gauge
theories with the 2d conformal blocks, which possess explicit Dotsenko-Fateev
matrix model (beta-ensemble) representations the latter being polylinear
combinations of Selberg integrals. The "pure gauge" limit of these matrix
models is, however, a non-trivial multiscaling large-N limit, which requires a
separate investigation. We show that in this pure gauge limit the Selberg
integrals turn into averages in a Brezin-Gross-Witten (BGW) model. Thus, the
Nekrasov function for pure SU(2) theory acquires a form very much reminiscent
of the AMM decomposition formula for some model X into a pair of the BGW
models. At the same time, X, which still has to be found, is the pure gauge
limit of the elliptic Selberg integral. Presumably, it is again a BGW model,
only in the Dijkgraaf-Vafa double cut phase.Comment: 21 page
Testing supersymmetry at the LHC through gluon-fusion production of a
  slepton pair

Renormalizable quartic couplings among new particles are typical of
supersymmetric models. Their detection could provide a test for supersymmetry,
discriminating it from other extensions of the Standard Model. Quartic
couplings among squarks and sleptons, together with the SU(3) gauge couplings
for squarks, allow a new realization of the gluon-fusion mechanism for
pair-production of sleptons at the one-loop level. The corresponding production
cross section, however, is at most of ${\cal O}(1) $fb for slepton and squark
masses of ${\cal O}(100) $GeV. We then extend our investigation to the
gluon-fusion production of sleptons through the exchange of Higgs bosons. The
cross section is even smaller, of ${\cal O}(0.1) $fb, if the exchanged Higgs
boson is considerably below the slepton-pair threshold, but it is enhanced when
it is resonant. It can reach ${\cal O}(10) $fb for the production of sleptons
of same-chirality, exceeding these values for $\widetilde{\tau}$'s of
opposite-chirality, even when chirality-mixing terms in the squark sector are
vanishing. The cross section can be further enhanced if these mixing terms are
nonnegligible, providing a potentially interesting probe of the Higgs sector,
in particular of parameters such as $A$, $\mu$, and $\tan\beta$.Comment: 28 pages, 11 figure
Two dimensional RG flows and Yang-Mills instantons

We study RG flow solutions in (1,0) six dimensional supergravity coupled to
an anti-symmetric tensor and Yang-Mills multiplets corresponding to a
semisimple group $G$. We turn on $G$ instanton gauge fields, with instanton
number $N$, in the conformally flat part of the 6D metric. The solution
interpolates between two (4,0) supersymmetric $AdS_3\times S^3$ backgrounds
with two different values of $AdS_3$ and $S^3$ radii and describes an RG flow
in the dual 2D SCFT. For the single instanton case and $G=SU(2)$, there exist a
consistent reduction ansatz to three dimensions, and the solution in this case
can be interpreted as an uplifted 3D solution. Correspondingly, we present the
solution in the framework of N=4 $(SU(2)\ltimes \mathbf{R}^3)^2$ three
dimensional gauged supergravity. The flows studied here are of v.e.v. type,
driven by a vacuum expectation value of a (not exactly) marginal operator of
dimension two in the UV. We give an interpretation of the supergravity solution
in terms of the D1/D5 system in type I string theory on K3, whose effective
field theory is expected to flow to a (4,0) SCFT in the infrared.Comment: 30 pages, clarifications of some notations added and typos correcte
Two loop renormalization of the n = 2 Wilson operator in the RI'/SMOM
  scheme

We compute the anomalous dimensions of the flavour non-singlet twist-2 Wilson
operators in the RI'/SMOM scheme at two loops in an arbitrary linear covariant
gauge. In addition we provide the full Green's function for these operators
inserted in a quark 2-point function at the symmetric subtraction point. The
three loop anomalous dimensions in the Landau gauge are also derived.Comment: 39 latex pages, 1 figure, 23 tables, anc directory contains txt file
  with anomalous dimensions, conversion functions and data given in the tables
  of the pape
Fivebrane instantons, topological wave functions and hypermultiplet
  moduli spaces

We investigate quantum corrections to the hypermultiplet moduli space M in
Calabi-Yau compactifications of type II string theories, with particular
emphasis on instanton effects from Euclidean NS5-branes. Based on the
consistency of D- and NS5-instanton corrections, we determine the topology of
the hypermultiplet moduli space at fixed string coupling, as previewed in
arXiv:1009.3026. On the type IIB side, we compute corrections from
(p,k)-fivebrane instantons to the metric on M (specifically, the correction to
the complex contact structure on its twistor space Z) by applying S-duality to
the D-instanton sum. For fixed fivebrane charge k, the corrections can be
written as a non-Gaussian theta series, whose summand for k=1 reduces to the
topological A-model amplitude. By mirror symmetry, instanton corrections
induced from the chiral type IIA NS5-brane are similarly governed by the wave
function of the topological B-model. In the course of this investigation we
clarify charge quantization for coherent sheaves and find hitherto unnoticed
corrections to the Heisenberg, monodromy and S-duality actions on M, as well as
to the mirror map for Ramond-Ramond fields and D-brane charges.Comment: 73 pages; v3: minor correction