pinecone/core-2020-05-10-deduplication huggingface dataset:
Search for the Standard Model Higgs boson in the decay channel
  H->ZZ(*)->4l with 4.8 fb-1 of pp collision data at sqrt(s) = 7 TeV with ATLAS

This Letter presents a search for the Standard Model Higgs boson in the decay
channel H->ZZ(*)->l+l-l'+l'-, where l,l'=e or mu, using proton-proton
collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector and
corresponding to an integrated luminosity of 4.8 fb^-1. The four-lepton mass
distribution is compared with Standard Model background expectations to derive
upper limits on the cross section of a Standard Model Higgs boson with a mass
between 110 GeV and 600 GeV. The mass ranges 134-156 GeV, 182-233 GeV, 256-265
GeV and 268-415 GeV are excluded at the 95% confidence level. The largest
upward deviations from the background-only hypothesis are observed for Higgs
boson masses of 125, 244 and 500 GeV with local significances of 2.1, 2.2 and
2.1 standard deviations, respectively. Once the look-elsewhere effect is
considered, none of these excesses are significant.Comment: 11 pages plus author list (26 pages total), 6 figures, 3 tables,
  corrected author list, matches published version in Physics Letters
Global velocity field and bubbles in the BCD Mrk86

We have studied the velocity field of the Blue Compact Dwarf galaxy Mrk86
(NGC2537) using data provided by 14 long-slit optical spectra. This kinematical
information is complemented with narrow-band ([OIII]5007A and Halpha) and
broad-band (B, V, Gunn-r and K) imaging. The analysis of the galaxy global
velocity field suggests that the ionized gas could be distributed in a rotating
inclined disk, with projected central angular velocity of Omega=34 km/s/kpc.
The comparison between the stellar, HI and modeled dark matter density profile,
indicates that the total mass within its optical radius is dominated by the
stellar component. Peculiarities observed in its velocity field can be
explained by irregularities in the ionized gas distribution or local motions
induced by star formation. Kinematical evidences for two expanding bubbles,
Mrk86-B and Mrk86-C, are given. They show expanding velocities of 34 km/s and
17 km/s, Halpha luminosities of 3x10^38 erg/s and 1.7x10^39 erg/s, and physical
radii of 374 and 120 pc, respectively. The change in the [SII]/Halpha,
[NII]/Halpha, [OII]/[OIII] and [OIII]/Hbeta line ratios with the distance to
the bubble precursor suggests a diminution in the ionization parameter and, in
the case of Mrk86-B, an enhancement of the shock-excited gas emission. The
optical-near-infrared colours of the bubble precursors are characteristic of
low metallicity star forming regions (0.2 Zsun) with burst strengths of about 1
per cent in mass.Comment: 14 pages, 12 PostScript figures, accepted for publication in MNRAS,
  also available at ftp://cutrex.fis.ucm.es/pub/OUT/gil/PAPERS
Low-temperature quenching of one-dimensional localised Frenkel excitons

We present a theoretical analysis of low-temperature quenching of
one-dimensional Frenkel excitons that are localised by moderate on-site
(diagonal) uncorrelated disorder. Exciton diffusion is considered as an
incoherent hopping over localization segments and is probed by the exciton
fluorescence quenching at point traps. The rate equation is used to calculate
the temperature dependence of the exciton quenching. The activation temperature
of the diffusion is found to be of the order of the width of the exciton
absorption band. We demonstrate that the intra-segment scattering is extremely
important for the exciton diffusion. We discuss also experimental data on the
fast exciton-exciton annihilation in linear molecular aggregates at low
temperatures.Comment: 7 pages, 3 figures, accepted to Chem. Phys. Let
Noncanonical Quantization of Gravity. I. Foundations of Affine Quantum
  Gravity

The nature of the classical canonical phase-space variables for gravity
suggests that the associated quantum field operators should obey affine
commutation relations rather than canonical commutation relations. Prior to the
introduction of constraints, a primary kinematical representation is derived in
the form of a reproducing kernel and its associated reproducing kernel Hilbert
space. Constraints are introduced following the projection operator method
which involves no gauge fixing, no complicated moduli space, nor any auxiliary
fields. The result, which is only qualitatively sketched in the present paper,
involves another reproducing kernel with which inner products are defined for
the physical Hilbert space and which is obtained through a reduction of the
original reproducing kernel. Several of the steps involved in this general
analysis are illustrated by means of analogous steps applied to one-dimensional
quantum mechanical models. These toy models help in motivating and
understanding the analysis in the case of gravity.Comment: minor changes, LaTeX, 37 pages, no figure
Stop Lepton Associated Production at Hadron Colliders

At hadron colliders, the search for R-parity violating supersymmetry can
probe scalar masses beyond what is covered by pair production processes. We
evaluate the next-to-leading order SUSY-QCD corrections to the associated stop
or sbottom production with a lepton through R-parity violating interactions. We
show that higher order corrections render the theoretical predictions more
stable with respect to variations of the renormalization and factorization
scales and that the total cross section is enhanced by a factor up to 70% at
the Tevatron and 50% at the LHC. We investigate in detail how the heavy
supersymmetric states decouple from the next-to-leading order process, which
gives rise to a theory with an additional scalar leptoquark. In this scenario
the inclusion of higher order QCD corrections increases the Tevatron reach on
leptoquark masses by up to 40 GeV and the LHC reach by up to 200 GeV.Comment: 10 pages and 4 figure
Supersymmetric Dark Matter - How Light Can the LSP Be?

Using a very minimal set of theoretical assumptions we derive a lower limit
on the LSP mass in the MSSM. We only require that the LSP be the lightest
neutralino, that it be responsible for the observed relic density and that the
MSSM spectrum respect the LEP2 limits. We explicitly do not require any further
knowledge about the MSSM spectrum or the mechanism of supersymmetry breaking.
Under these assumptions we determine a firm lower limit on the neutralino LSP
mass of $18\gev$. We estimate the effect of improved limits on the cold dark
matter relic density as well as the effects of improved LEP2-type limits from a
first stage of TESLA on the allowed range of neutralino LSP masses.Comment: 12 pages, 3 Figures, v2: published versio
The Herschel Gould Belt Survey in Chamaeleon II - Properties of cold
  dust in disks around young stellar objects

We report on the Herschel Gould Belt survey (HGBS) of ChaII, focusing on the
detection of Class I to III young stellar objects (YSOs). We aim at
characterizing the circumstellar material around these YSOs and understanding
which disk parameters are most likely constrained by the new HGBS data. We
recovered 29 out of the 63 known YSOs in ChaII with a detection in at least one
of the PACS/SPIRE pass-bands: 3 Class I YSOs (i.e.,100%), 1 Flat source (i.e.,
50%), 21 Class II objects (i.e., 55%), 3 Class III objects (i.e, 16%) and the
unclassified source IRAS 12522-7640. We explore PACS/SPIRE colors of this
sample and present modeling of their SEDs using the RADMC-2D radiative transfer
code. We find that YSO colors are confined in specific regions of PACS/SPIRE
color-color diagrams. These color ranges are expected to be only marginally
contaminated by extragalactic sources and field stars and, hence, provide a
useful YSO selection tool when applied altogether. We were able to model the
SED of 26 out of the 29 detected YSOs. We discuss the degeneracy/limitations of
our SED fitting results and adopt the Bayesian method to estimate the
probability of different values for the derived disk parameters. The Cha II
YSOs present typical disk inner radii around 0.1 AU. The lower limit to Rc is
typically around 50 AU. The lower limits to Mdisk are proportional to the
stellar masses with a typical 0.3% ratio, i.e., in the range estimated in the
literature for young Class II stars and brown dwarfs across a broad range of
stellar masses. The estimated flaring angles, although very uncertain, point
towards rather flat disks (1+phi less than 1.2), as found for low-mass M-type
YSO samples in other star forming regions. Thus, our results support the idea
that disk properties show a dependence on stellar properties.Comment: 17 pages, 9 figure
Mid- to far infrared properties of star-forming galaxies and active
  galactic nuclei

We study the mid- to far-IR properties of a 24um-selected flux-limited sample
(S24 > 5mJy) of 154 intermediate redshift (<z>~0.15), infrared luminous
galaxies, drawn from the 5MUSES survey. By combining existing mid-IR
spectroscopy and new Herschel SPIRE submm photometry from the HerMES program,
we derived robust total infrared luminosity (LIR) and dust mass (Md) estimates
and infered the relative contribution of the AGN to the infrared energy budget
of the sources. We found that the total infrared emission of galaxies with weak
6.2um PAH emission (EW<0.2um) is dominated by AGN activity, while for galaxies
with EW>0.2um more than 50% of the LIR arises from star formation. We also
found that for galaxies detected in the 250-500um Herschel bands an AGN has a
statistically insignificant effect on the temperature of the cold dust and the
far-IR colours of the host galaxy, which are primarily shaped by star formation
activity. For star-forming galaxies we reveal an anti-correlation between the
LIR-to-rest-frame 8um luminosity ratio, IR8 = LIR\L8, and the strength of PAH
features. We found that this anti-correlation is primarily driven by variations
in the PAHs emission, and not by variations in the 5-15um mid-IR continuum
emission. Using the [NeIII]/[NeII] line ratio as a tracer of the hardness of
the radiation field, we confirm that galaxies with harder radiation fields tend
to exhibit weaker PAH features, and found that they have higher IR8 values and
higher dust-mass-weighted luminosities (LIR/Md), the latter being a proxy for
the dust temperature (Td). We argue that these trends originate either from
variations in the environment of the star-forming regions or are caused by
variations in the age of the starburst. Finally, we provide scaling relations
that will allow estimating LIR, based on single-band observations with the
mid-infrared instrument, on board the upcoming JWST.Comment: Accepted for publication in A&
Long-term TeV and X-ray Observations of the Gamma-ray Binary HESS
  J0632+057

HESS J0632+057 is the only gamma-ray binary known so far whose position in
the sky allows observations with ground-based observatories both in the
northern and southern hemispheres. Here we report on long-term observations of
HESS J0632+057 conducted with the VERITAS and H.E.S.S. Cherenkov Telescopes and
the X-ray Satellite Swift, spanning a time range from 2004 to 2012 and covering
most of the system's orbit. The VHE emission is found to be variable, and is
correlated with that at X-ray energies. An orbital period of $315 ^{+6}_{-4}$
days is derived from the X-ray data set, which is compatible with previous
results, $P = (321 \pm 5$) days. The VHE light curve shows a distinct maximum
at orbital phases close to 0.3, or about 100 days after periastron passage,
which coincides with the periodic enhancement of the X-ray emission.
Furthermore, the analysis of the TeV data shows for the first time a
statistically significant ($> 6.5 \sigma$) detection at orbital phases
0.6--0.9. The obtained gamma-ray and X-ray light curves and the correlation of
the source emission at these two energy bands are discussed in the context of
the recent ephemeris obtained for the system. Our results are compared to those
reported for other gamma-ray binaries.Comment: 35 pages, 8 figures, accepted for publication in Ap
One-loop renormalization in a toy model of Horava-Lifshitz gravity

We present a one loop calculation in the context of Horava-Lifshitz gravity.
Due to the complexity of the calculation in the full theory we focus here on
the study of a toy model, namely the conformal reduction of the z=2 projectable
theory in 2+1 dimensions. For this value of the dimension there are no
gravitons, hence the conformal mode is the only physical degree of freedom, and
thus we expect our toy model to lead to qualitatively correct answers regarding
the perturbative renormalization of the full theory. We find that Newton's
constant (dimensionless in Horava-Lifshitz gravity) is asymptotically free.
However, the DeWitt supermetric approaches its Weyl invariant form with the
same speed and the effective interaction coupling remains constant along the
flow. In other words, the would-be asymptotic freedom associated to the running
Newton's constant is exactly balanced by the strong coupling of the scalar mode
as the Weyl invariant limit is approached. We conclude that in such model the
UV limit is singular at one loop order, and we argue that a similar phenomenon
can be expected in the full theory, even in higher dimensions.Comment: 18 pages. v2: corrected some misprints, added 3 references, some
  clarifying comments and a new appendi
Studies of azimuthal dihadron correlations in ultra-central PbPb
  collisions at sqrt(s[NN]) = 2.76 TeV

Azimuthal dihadron correlations of charged particles have been measured in
PbPb collisions at sqrt(s[NN]) = 2.76 TeV by the CMS collaboration, using data
from the 2011 LHC heavy-ion run. The data set includes a sample of
ultra-central (0-0.2% centrality) PbPb events collected using a trigger based
on total transverse energy in the hadron forward calorimeters and the total
multiplicity of pixel clusters in the silicon pixel tracker. A total of about
1.8 million ultra-central events were recorded, corresponding to an integrated
luminosity of 120 inverse microbarns. The observed correlations in
ultra-central PbPb events are expected to be particularly sensitive to
initial-state fluctuations. The single-particle anisotropy Fourier harmonics,
from v[2] to v[6], are extracted as a function of particle transverse momentum.
At higher transverse momentum, the v[2] harmonic becomes significantly smaller
than the higher-order v[n] (n greater than or equal to 3). The pt-averaged v[2]
and v[3] are found to be equal within 2%, while higher-order v[n] decrease as n
increases. The breakdown of factorization of dihadron correlations into
single-particle azimuthal anisotropies is observed. This effect is found to be
most prominent in the ultra-central PbPb collisions, where the initial-state
fluctuations play a dominant role. A comparison of the factorization data to
hydrodynamic predictions with event-by-event fluctuating initial conditions is
also presented.Comment: Replaced with published version. Added journal reference and DO
Measurement of dijet cross sections in pp collisions at 7 TeV
  centre-of-mass energy using the ATLAS detector

Double-differential dijet cross sections measured in pp collisions at the LHC
with a 7 TeV centre-of-mass energy are presented as functions of dijet mass and
rapidity separation of the two highest-pT jets. These measurements are obtained
using data corresponding to an integrated luminosity of 4.5/fb, recorded by the
ATLAS detector in 2011. The data are corrected for detector effects so that
cross sections are presented at the particle level. Cross sections are measured
up to 5 TeV dijet mass using jets reconstructed with the anti-kt algorithm for
values of the jet radius parameter of 0.4 and 0.6. The cross sections are
compared with next-to-leading-order perturbative QCD calculations by NLOJET++
corrected to account for non-perturbative effects. Comparisons with POWHEG
predictions, using a next-to-leading-order matrix element calculation
interfaced to a parton-shower Monte Carlo simulation, are also shown.
Electroweak effects are accounted for in both cases. The quantitative
comparison of data and theoretical predictions obtained using various
parameterizations of the parton distribution functions is performed using a
frequentist method. An example setting a lower limit on the compositeness scale
for a model of contact interactions is presented, showing that the unfolded
results can be used to constrain contributions to dijet production beyond that
predicted by the Standard Model.Comment: 53 pages plus author list (75 pages total), 14 figures, 15 tables,
  submitted to JHEP. All figures including auxiliary figures are available at
  http://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2012-03/ Revision
  matches published versio
Covariant Non-Commutative Space-Time

We introduce a covariant non-commutative deformation of 3+1-dimensional
conformal field theory. The deformation depends on a short-distance scale
\ell_p, and thus breaks scale invariance, but preserves all space-time
isometries. The non-commutative algebra is defined on space-times with non-zero
constant curvature, i.e. dS_4 or AdS_4. The construction makes essential use of
the representation of CFT tensor operators as polynomials in an auxiliary
polarization tensor. The polarization tensor takes active part in the
non-commutative algebra, which for dS_4 takes the form of so(5,1), while for
AdS_4 it assembles into so(4,2). The structure of the non-commutative
correlation functions hints that the deformed theory contains gravitational
interactions and a Regge-like trajectory of higher spin excitations.Comment: 20 pages, 1 figur
Calabi-Yau threefolds with large h^{2, 1}

We carry out a systematic analysis of Calabi-Yau threefolds that are
elliptically fibered with section ("EFS") and have a large Hodge number h^{2,
1}. EFS Calabi-Yau threefolds live in a single connected space, with regions of
moduli space associated with different topologies connected through transitions
that can be understood in terms of singular Weierstrass models. We determine
the complete set of such threefolds that have h^{2, 1} >= 350 by tuning
coefficients in Weierstrass models over Hirzebruch surfaces. The resulting set
of Hodge numbers includes those of all known Calabi-Yau threefolds with h^{2,
1} >= 350, as well as three apparently new Calabi-Yau threefolds. We speculate
that there are no other Calabi-Yau threefolds (elliptically fibered or not)
with Hodge numbers that exceed this bound. We summarize the theoretical and
practical obstacles to a complete enumeration of all possible EFS Calabi-Yau
threefolds and fourfolds, including those with small Hodge numbers, using this
approach.Comment: 44 pages, 5 tables, 5 figures; v2: minor corrections; v3: minor
  corrections, moved figure; v4: typo in Table 2 correcte
On consistent boundary conditions for c = 1 string theory

We introduce a new parametrisation for the Fermi sea of the c = 1 matrix model. This leads to a simple derivation of the scattering matrix, and a calculation of boundary corrections in the corresponding 1+1--dimensional string theory. The new parametrisation involves relativistic chiral fields, rather than the non-relativistic fields of the usual formulations. The calculation of the boundary corrections, following recent work of Polchinski, allows us to place restrictions on the boundary conditions in the matrix model. We provide a consistent set of boundary conditions, but believe that they need to be supplemented by some more subtle relationship between the space-time and matrix model. Inspired by these boundary conditions, some thoughts on the black hole in c=1 string theory are presented
The action operator for continuous time histories

We define the action operator for the History Projection Operator consistent histories theory, as the quantum analogue of the classical action functional, for the simple harmonic oscillator in one dimention. We conclude that the action operator is the generator of time transformations, and is associated with the two types of time-evolution of the standard quantum theory: the wave-packet reduction and the Heisenberg time-evolution. We construct corresponding classical histories and demonstrate the relevance with the quantum histories. Finally, we show the appearance of the action operator in the expression for the decoherence functional
Drell-Yan and $J/\psi$ Production in High Energy Proton-Nucleus and Nucleus-Nucleus Collisions

The distributions of outgoing protons and charged hadrons in high energy proton-nucleus collisions are described rather well by a linear extrapolation from proton-proton collisions. This linear extrapolation is applied to precisely measured Drell-Yan cross sections for 800 GeV protons incident on a variety of nuclear targets. The deviation from linear scaling in the atomic number A can be accounted for by energy degradation of the proton as it passes through the nucleus if account is taken of the time delay of particle production due to quantum coherence. We infer an average proper coherence time of 0.4 +/- 0.1 fm/c. Then we apply the linear extrapolation to measured J/psi production cross sections for 200 and 450 GeV/c protons incident on a variety of nuclear targets. Our analysis takes into account energy loss of the beam proton, the time delay of particle production due to quantum coherence, and absorption of the J/psi on nucleons. The best representation is obtained for a coherence time of 0.5 fm/c, which is consistent with Drell-Yan production, and an absorption cross section of 3.6 mb, which is consistent with the value deduced from photoproduction of the J/psi on nuclear targets. Finally, we compare to recent J/psi data from S+U and Pb+Pb collisions at the SPS. The former are reproduced reasonably well with no new parameters, but not the latter
Two-proton correlations from 158 AGeV Pb+Pb central collisions

The two-proton correlation function at midrapidity from Pb+Pb central
collisions at 158 AGeV has been measured by the NA49 experiment. The results
are compared to model predictions from static thermal Gaussian proton source
distributions and transport models RQMD and VENUS. An effective proton source
size is determined by minimizing CHI-square/ndf between the correlation
functions of the data and those calculated for the Gaussian sources, yielding
3.85 +-0.15(stat.) +0.60-0.25(syst.) fm. Both the RQMD and the VENUS model are
consistent with the data within the error in the correlation peak region.Comment: RevTeX style, 6 pages, 4 figures, 1 table. More discussion are added
  about the structure on the tail of the correlation function. The systematic
  error is revised. To appear in Phys. Lett.