pinecone/core-2020-05-10-deduplication huggingface dataset:
Systematic decomposition of the neutrinoless double beta decay operator

We discuss the systematic decomposition of the dimension nine neutrinoless double beta decay operator, focusing on mechanisms with potentially small contributions to neutrino mass, while being accessible at the LHC. We first provide a (d = 9 tree-level) complete list of diagrams for neutrinoless double beta decay. From this list one can easily recover all previously discussed contributions to the neutrinoless double beta decay process, such as the celebrated mass mechanism or ¿exotics¿, such as contributions from left-right symmetric models, R-parity violating supersymmetry and leptoquarks. More interestingly, however, we identify a number of new possibilities which have not been discussed in the literature previously. Contact to earlier works based on a general Lorentz-invariant parametrisation of the neutrinoless double beta decay rate is made, which allows, in principle, to derive limits on all possible contributions. We furthermore discuss possible signals at the LHC for mediators leading to the short-range part of the amplitude with one specific example. The study of such contributions would gain particular importance if there were a tension between different measurements of neutrino mass such as coming from neutrinoless double beta decay and cosmology or single beta decay
Gravity Mediation Retrofitted

Most discussion of metastable dynamical supersymmetry breaking (MDSB) has
focussed on low energy breaking, as in gauge mediation. It is of interest to
consider possible implications for intermediate scale breaking ("gravity
mediation"), especially as the early LHC results suggest the possibility that
supersymmetry, if broken at relatively low energies, might be tuned. A somewhat
high scale for susy breaking could ameliorate the usual flavor problems of
gravity mediation, resolve the question of cosmological moduli, and account for
a Higgs with mass well above $M_Z$. We study MDSB in gravity mediation,
especially retrofitted models in which discrete $R$ symmetries play an
important role, considering questions including implications of symmetries for
$B$ and $A$ terms, and the genericity of split supersymmetry.Comment: 16 pages. Notational errors fixed, references adde
On Non-Gaussianities in Two-Field Poly-Instanton Inflation

In the context of Type IIB LARGE volume orientifold setup equipped with
poly-instanton corrections, the standard single-field poly-instanton inflation
driven by a 'Wilson' divisor volume modulus is generalized by the inclusion of
respective axion modulus. This two-field dynamics results in a "Roulette" type
inflation with the presence of several inflationary trajectories which could
produce 50 (or more) e-foldings. The evolution of various trajectories along
with physical observables are studied. The possibility of generating primordial
non-Gaussianities in the slow-roll as well as in the beyond slow-roll region is
investigated. We find that although the non- linearity parameters are quite
small during the slow-roll regime, the same are significantly enhanced in the
beyond slow-roll regime investigated up to the end of inflation.Comment: 37 pages, 6 figures, arXiv admin note: text overlap with
  arXiv:1208.1160 in review section 2, References and Table.2 added, Typos
  fixed, published versio
The a-theorem and conformal symmetry breaking in holographic RG flows

We study holographic models describing an RG flow between two fixed points
driven by a relevant scalar operator. We show how to introduce a spurion field
to restore Weyl invariance and compute the anomalous contribution to the
generating functional in even dimensional theories. We find that the
coefficient of the anomalous term is proportional to the difference of the
conformal anomalies of the UV and IR fixed points, as expected from anomaly
matching arguments in field theory. For any even dimensions the coefficient is
positive as implied by the holographic a-theorem. For flows corresponding to
spontaneous breaking of conformal invariance, we also compute the two-point
functions of the energy-momentum tensor and the scalar operator and identify
the dilaton mode. Surprisingly we find that in the simplest models with just
one scalar field there is no dilaton pole in the two-point function of the
scalar operator but a stronger singularity. We discuss the possible
implications.Comment: 50 pages. v2: minor changes, added references, extended discussion.
  v3: we have clarified some of the calculations and assumptions, results
  unchanged. v4: published version in JHE
Cosmological perturbations in warm-tachyon inflationary universe model
  with viscous pressure on the brane

We study warm-viscous inflationary universe model on the brane, in a tachyon
field theory. We obtain the general conditions which are required for this
model to be realizable. In longitudinal gauge, the primoradial perturbation
parameters are found in great details, using slow-roll and quasi-stable
approximations. The general expressions of the tensor-to-scalar ratio, scalar
spectral index and its running are found. We derive the characteristics of the
inflationary universe model by using an effective exponential potential in two
cases: 1- Dissipative parameter $\Gamma$ and bulk viscous parameter $\zeta$ are
constant parameters. 2- Dissipative parameter as a function of tachyon field
$\phi$ and bulk viscous parameter as a function of radiation-matter mixture
energy density $\rho$. The parameters of the model are restricted by recent
observational data from the seven-year Wilkinson microwave anisotropy probe
(WMAP7).Comment: 27 pages, 6 figures, accepted for publication by JHE
Heavy Squarks and Light Sleptons in Gauge Mediation ~From the viewpoint
  of 125 GeV Higgs Boson and Muon g-2~

In the framework of gauge mediation models, we investigate scenarios with
heavy squarks and light sleptons, motivated by the recent discovery of the
Higgs boson and the deviation of the muon anomalous magnetic moment (g-2) from
the SM prediction. We show that only models with a messenger multiplet in the
adjoint representation of SU(5) GUT gauge group are the unique possibility that
sleptons are light enough to explain the muon g-2 in the minimal setup. We also
show that, if there is an additional source of the Higgs soft masses, the muon
g-2 can be explained with messenger multiples in the fundamental representation
of SU(5) with the help of the light higgsino. Some phenomenological aspects of
these models are also discussed.Comment: 17 pages, 3 figures; figures updated; version to be publishe
A perturbative framework for jet quenching.

We present a conceptually new framework for describing jet evolution in the dense medium produced in ultra-relativistic nucleus-nucleus collisions using perturbative QCD and its implementation into the Monte Carlo event generator Jewel. The rescattering of hard partons in the medium is modelled by infrared continued pQCD matrix elements supplemented with parton showers. The latter approximate higher order real-emission matrix elements and thus generate medium-induced gluon emissions. The interplay between different emissions is governed by their formation times. The destructive interference between subsequent scattering processes, the non-Abelian version of the Landau-Pomeranchuk-Migdal effect, is also taken into account. In this way the complete radiation pattern is consistently treated in a uniform way. Results obtained within this minimal and theoretically well constrained framework are compared with a variety of experimental data susceptible to jet-quenching effects at both RHIC and the LHC. Overall, a good agreement between data and simulation is found. This new framework also allows to identify and quantify the dominant uncertainties in the simulation, and we show some relevant examples for this
The SU(3)-invariant sector of new maximal supergravity

We investigate the SU(3)-invariant sector of the one-parameter family of SO(8) gauged maximal supergravities that has been recently discovered. To this end, we construct the N=2 truncation of this theory and analyse its full vacuum structure. The number of critical point is doubled and includes new N=0 and N=1 branches. We numerically exhibit the parameter dependence of the location and cosmological constant of all extrema. Moreover, we provide their analytic expressions for cases of special interest. Finally, while the mass spectra are found to be parameter independent in most cases, we show that the novel non-supersymmetric branch with SU(3) invariance provides the first counterexample to this
Heterotic-type II duality in twistor space

Heterotic string theory compactified on a K3 surface times T^2 is believed to
be equivalent to type II string theory on a suitable Calabi-Yau threefold. In
particular, it must share the same hypermultiplet moduli space. Building on the
known twistorial description on the type II side, and on recent progress on the
map between type II and heterotic moduli in the `double scaling' limit (where
both the type II and heterotic strings become classical), we provide a new
twistorial construction of the hypermultiplet moduli space in this limit which
is adapted to the symmetries of the heterotic string. We also take steps
towards understanding the twistorial description for heterotic worldsheet
instanton corrections away from the double scaling limit. As a spin-off, we
obtain a twistorial description of a class of automorphic forms of SO(4,n,Z)
obtained by Borcherds' lift.Comment: 29 pages; the duality map is restricted to heterotic vacua without
  bundle moduli, for reasons explained in footnote
A note on "symmetric" vielbeins in bimetric, massive, perturbative and
  non perturbative gravities

We consider a manifold endowed with two different vielbeins $E^{A}{}_{\mu}$
and $L^{A}{}_{\mu}$ corresponding to two different metrics $g_{\mu\nu}$ and
$f_{\mu\nu}$. Such a situation arises generically in bimetric or massive
gravity (including the recently discussed version of de Rham, Gabadadze and
Tolley), as well as in perturbative quantum gravity where one vielbein
parametrizes the background space-time and the other the dynamical degrees of
freedom. We determine the conditions under which the relation $g^{\mu\nu}
E^{A}{}_{\mu} L^{B}{}_{\nu} = g^{\mu\nu} E^{B}{}_{\mu} L^{A}{}_{\nu}$ can be
imposed (or the "Deser-van Nieuwenhuizen" gauge chosen). We clarify and correct
various statements which have been made about this issue.Comment: 20 pages. Section 7, prop. 6 and 7. added. Some results made more
  precis
Dynamical Quarkonia Suppression in a QGP-Brick

I address the effect that a temperature dependent potential has on the
suppression of heavy quarkonia states in deconfined hadronic matter. I focus on
a simple medium: a homogenous, fixed temperature and deconfined system with a
finite lifetime (QGP-brick). Assuming that all the interactions of a heavy
quark anti-quark ($Q-\bar Q$) pair with the medium can be recast into an
in-medium potential, I solve the time dependent Schr\"odinger equation to
evolve the density matrix which describes the hard pair production and its
connection to the final distribution of hadrons after the medium disappears.
For those temperatures in which bound states survive in the medium, I find a
non-trivial dependence of the production of excited quarkonia states on the
in-medium levels, due to the mixing of vacuum and in-medium wave functions.
This mixing leads, in particular, to the enhancement of the relative abundance
of 2S to 1S states for those systems in which the in-medium ground state of the
$Q-\bar Q$ system is dissolved or close to threshold. I also explore quarkonia
production in a non-homogeneous expanding medium and find that the finite
formation time effects arising from the low binding energies of in-medium
states lead to the insensitivity of the heavy mesons yield to the hottest part
of the system evolution.Comment: 21 pages, 19 figure
Consistently Constrained SL(N) WZWN Models and Classical Exchange
  Algebra

Currents of the SL(N) WZWN model are constrained so that the remaining
symmetry is a symmetry of constrained currents as well. Such consistency
enables us to study the Poisson structure of constrained SL(N) WZWN models
properly. We establish the Poisson brackets which satisfy the Jacobi identities
owing to the classical Yang-Baxter equation. The Virasoro algebra is shown by
using them. An SL(N) conformal primary is constructed. It satisfies a quadratic
algebra, which might become an exchange algebra by its quantum deformation.Comment: 26 pages, v3: matches published version, v2: typos correcte
Accelerated expansion from ghost-free bigravity: a statistical analysis
  with improved generality

We study the background cosmology of the ghost-free, bimetric theory of
gravity. We perform an extensive statistical analysis of the model using both
frequentist and Bayesian frameworks and employ the constraints on the expansion
history of the Universe from the observations of supernovae, the cosmic
microwave background and the large scale structure to estimate the model's
parameters and test the goodness of the fits. We explore the parameter space of
the model with nested sampling to find the best-fit chi-square, obtain the
Bayesian evidence, and compute the marginalized posteriors and mean
likelihoods. We mainly focus on a class of sub-models with no explicit
cosmological constant (or vacuum energy) term to assess the ability of the
theory to dynamically cause a late-time accelerated expansion. The model
behaves as standard gravity without a cosmological constant at early times,
with an emergent extra contribution to the energy density that converges to a
cosmological constant in the far future. The model can in most cases yield very
good fits and is in perfect agreement with the data. This is because many
points in the parameter space of the model exist that give rise to
time-evolution equations that are effectively very similar to those of the
$\Lambda$CDM. This similarity makes the model compatible with observations as
in the $\Lambda$CDM case, at least at the background level. Even though our
results indicate a slightly better fit for the $\Lambda$CDM concordance model
in terms of the $p$-value and evidence, none of the models is statistically
preferred to the other. However, the parameters of the bigravity model are in
general degenerate. A similar but perturbative analysis of the model as well as
more data will be required to break the degeneracies and constrain the
parameters, in case the model will still be viable compared to the
$\Lambda$CDM.Comment: 42 pages, 9 figures; typos corrected in equations (2.12), (2.13),
  (3.7), (3.8) and (3.9); more discussions added (footnotes 5, 8, 10 and 13)
  and abstract, sections 4.2, 4.3 and 5 (conclusions) modified in response to
  referee's comments; references added; acknowledgements modified; all results
  completely unchanged; matches version accepted for publication in JHE
Semi-local quantum criticality in string/M-theory.

Semi-local quantum critical behaviour in D − 1 spacetime dimensions can be holographically described by metrics that are conformal to AdS 2 ×R D−2   , with the conformal factor characterised by a parameter η. We analyse such “η-geometries” in a top-down setting by focussing on the U(1)4 truncation of D = 4 N = 8 gauged supergravity. The model has extremal black hole solutions carrying three non-zero electric or magnetic charges which approach AdS 4 in the UV and an η = 1 geometry in the IR. Adding a fourth charge provides a mechanism to resolve the singularity of the η-geometry, replacing it with an AdS 2 ×R 2    factor in the IR, while maintaining a large region where the η-geometry scaling is approximately valid. Some of the magnetically charged black hole solutions preserve supersymmetry while others just preserve it in the IR. Finally, we show that η-geometries, with various values of η, can be obtained from the dimensional reduction of geometries consisting of AdS or Lifshitz geometries with flat directions
The Pauli exclusion principle at strong coupling: Holographic matter and
  momentum space

For free fermions at finite density, the Pauli exclusion principle is
responsible for the existence of a Fermi surface and the consequent presence of
low energy spectral weight over a finite range of momenta. We investigate the
extent to which this effect occurs in strongly interacting quantum matter with
a holographic dual. We obtain the low energy current-current spectral weight in
two holographic frameworks at finite density: systems exhibiting semi-local
quantum criticality (with a low temperature entropy density vanishing like s ~
T^eta), and a probe D3/D5 system. For the semi-local theory with 0 < eta < 2 we
find a sharp discontinuity in the transverse spectral weight at a nonzero
momentum k_*. The case eta = 1 is found to have additional symmetries and is
soluble even at nonzero temperature. We show that this case exhibits a robust
linear in temperature resistivity in the presence of random charged impurities.
For the probe D3/D5 system we find an analytic expression for the low energy
spectral weight as a function of momentum. The spectral weight is supported
below a specific momentum k_* and is exponentially suppressed at higher
momenta.Comment: 1+31 pages. PDFLaTeX. 2 figure
Reconstruction of Higgs bosons in the di-tau channel via 3-prong decay

We propose a method for reconstructing the mass of a particle, such as the
Higgs boson, decaying into a pair of tau leptons, of which one subsequently
undergoes a 3-prong decay. The kinematics is solved using information from the
visible decay products, the missing transverse momentum, and the 3-prong tau
decay vertex, with the detector resolution taken into account using a
likelihood method. The method is shown to give good discrimination between a
125 GeV Higgs boson signal and the dominant backgrounds, such as Z decays to
tau tau and W plus jets production. As a result, we find an improvement,
compared to existing methods for this channel, in the discovery potential, as
well as in measurements of the Higgs boson mass and production cross section
times branching ratio.Comment: 19 pages, 8 figure
Recipes and Ingredients for Neutrino Mass at Loop Level

The large hierarchy between the neutrino mass scale and that of the other
fermions seems to be unnatural from a theoretical point of view. Various
strategies have been devised in order to generate naturally small values of
neutrino masses. One of these techniques is neutrino mass generation at the
loop level which requires a mechanism, e.g., a symmetry, to forbid the lower
order contributions. Here, we study in detail the conditions on this type of
symmetries. We put special emphasis on the discrete Z_n symmetries as a simple
example but our results can be also extended to more general groups. We find
that regardless of the details of the symmetry, in certain cases the existence
of a lower order contribution to neutrino masses can be determined by the
topology of the diagrams with a given number of loops. We discuss the lepton
flavor violating rare decays as well as (g-2)_\mu in this class of models,
which generically appear at the one loop level. Typically the imposed symmetry
has important implications for dark matter, with the possibility of stabilizing
one or even multiple dark matter candidates.Comment: 25 pages, 11 figures; v2: references and section about DM added,
  version published in JHE
Competing orders in M-theory : superfluids, stripes and metamagnetism.

We analyse the infinite class of d = 3 CFTs dual to skew-whiffed AdS 4 × SE 7 solutions of D = 11 supergravity at finite temperature and charge density and in the presence of a magnetic field. We construct black hole solutions corresponding to the unbroken phase, and at zero temperature some of these become dyonic domain walls of an Einstein-Maxwell-pseudo-scalar theory interpolating between AdS 4 in the UV and new families of dyonic AdS 2 ×R 2    solutions in the IR. The black holes exhibit both diamagnetic and paramagnetic behaviour. We analyse superfluid and striped instabilities and show that for large enough values of the magnetic field the superfluid instability disappears while the striped instability remains. For larger values of the magnetic field there is also a first-order metamagnetic phase transition and at zero temperature these black hole solutions exhibit hyperscaling violation in the IR with dynamical exponent z = 3/2 and θ = −2
Holography and hydrodynamics for EMD theory with two Maxwell fields

We use `generalized dimensional reduction' to relate a specific
Einstein-Maxwell-Dilaton (EMD) theory, including two gauge fields, three
neutral scalars and an axion, to higher-dimensional AdS gravity (with no
higher-dimensional Maxwell field). In general, this is a dimensional reduction
over compact Einstein spaces in which the dimension of the compact space is
continued to non-integral values. Specifically, we perform a non-diagonal
Kaluza-Klein (KK) reduction over a torus, involving two KK gauge fields. Our
aim is to determine the holographic dictionary and hydrodynamic behaviour of
the lower-dimensional theory by performing the generalized dimensional
reduction on AdS. We study a specific example of a black brane carrying a wave,
whose universal sector is described by gravity coupled to two Maxwell fields,
three neutral scalars and an axion, and compute the first order transport
coefficients of the dual theory. In these theories $\hat{\z}_s / \hat{\eta} <
2(1(d-1)-\hat{c}_s^2)$, where $\hat{c}_s$ is the speed of sound, violating a
conjectured bound, but an alternative bound is satisfied.Comment: 50 pages, no figure
Measurement of ZZ production in pp collisions at √ s= 7 TeV and limits on anomalous ZZZ and ZZγ couplings with the ATLAS detector

Journal of High Energy Physics 2013.3 (2013): 128 reproduced by permission of Scuola Internazionale Superiore di Studi Avanzati (SISSA)Artículo escrito por un elevado número de autores, solo se referencian el que aparece en primer lugar, el nombre del grupo de colaboración, si le hubiere, y los autores pertenecientes a la UAMA measurement of the ZZ production cross section in proton-proton collisions at √ = 7 TeV using data recorded by the ATLAS experiment at the Large Hadron Collider is presented. In a data sample corresponding to an integrated luminosity of 4.6 fb-1 collected in 2011, events are selected that are consistent either with two Z bosons decaying to electrons or muons or with one Z boson decaying to electrons or muons and a second Z boson decaying to neutrinos. The ZZ → ℓ + ℓ - ℓ ′+ ℓ ′- and ZZ → ℓ + ℓ - ℓv̄v cross sections are measured in restricted phase-space regions. These results are then used to derive the total cross section for ZZ events produced with both Z bosons in the mass range 66 to 116 GeV, σZZ tot = 6.7 ± 0.7 (stat.) -0.3 +0.4 (syst.) ± 0.3 (lumi.) pb, which is consistent with the Standard Model prediction of 5.89-0.18 +0.22 pb calculated at next-to-leading order in QCD. The normalized differential cross sections in bins of various kinematic variables are presented. Finally, the differential event yield as a function of the transverse momentum of the leading Z boson is used to set limits on anomalous neutral triple gauge boson couplings in ZZ productio