pinecone/core-2020-05-10-deduplication huggingface dataset:
Theory of Light Hydrogenlike Atoms

The present status and recent developments in the theory of light hydrogenic
atoms, electronic and muonic, are extensively reviewed. The discussion is based
on the quantum field theoretical approach to loosely bound composite systems.
The basics of the quantum field theoretical approach, which provide the
framework needed for a systematic derivation of all higher order corrections to
the energy levels, are briefly discussed. The main physical ideas behind the
derivation of all binding, recoil, radiative, radiative-recoil, and
nonelectromagnetic spin-dependent and spin-independent corrections to energy
levels of hydrogenic atoms are discussed and, wherever possible, the
fundamental elements of the derivations of these corrections are provided. The
emphasis is on new theoretical results which were not available in earlier
reviews. An up-to-date set of all theoretical contributions to the energy
levels is contained in the paper. The status of modern theory is tested by
comparing the theoretical results for the energy levels with the most precise
experimental results for the Lamb shifts and gross structure intervals in
hydrogen, deuterium, and helium ion $He^+$, and with the experimental data on
the hyperfine splitting in muonium, hydrogen and deuterium.Comment: 230 pages, 106 figures, 24 tables. Discussion of muonic hydrogen is
  added, list of references expanded, some minor corrections and amendment
$T$-Odd Effects in Unpolarized Drell-Yan Scattering

We consider the leading twist $T$-odd contributions as the dominant source of
the $\cos 2\phi$ azimuthal asymmetry in unpolarized $p\bar{p}\to \mu\mu^+ X$
dilepton production in Drell-Yan Scattering. This asymmetry contains
information on the distribution of quark transverse spin in an unpolarized
proton. In a parton-spectator framework we estimate these asymmetries at $50
{\rm GeV}$ center of mass energy. This azimuthal asymmetry is interesting in
light of proposed experiments at GSI, where an anti-proton beam is ideal for
studying the transversity properties of quarks due to the dominance of {\em
valence} quark effects.Comment: 8 pages, 8 figure
On Statistical Mechanics Developments of Clan Concept in Multiparticle
  Production

Clan concept has been introduced in multiparticle dynamics in order to
interpret the wide occurrence of negative binomial (NB) regularity in n-charged
particle multiplicity distributions (MDs) in various high energy collisions.
The centrality of clan concept led to the attempt to justify its occurrence
within a statistical model of clan formation and evolution. In this framework
all thermodynamical potentials have been explicitly calculated in terms of NB
parameters. Interestingly it was found that NB parameter k corresponds to the
one particle canonical partition function. The goal of this paper is to explore
a possible temperature and volume dependence of parameter k in various classes
of events in high energy hadron-hadron collisions. It is shown that the
existence of a phase transition at parton level from the ideal clan gas
associated to the semihard component with k>1 to the ideal clan gas of the hard
component with k<1 implies a discontinuity in the average number of particles
at hadron level.Comment: 20 pages, latex, no figures; v2: the description of the framework has
  been considerably expanded, and the main body has been reorganized for
  clarit
Dynamics of isolated-photon plus jet production in pp collisions at
  sqrt(s)=7 TeV with the ATLAS detector

The dynamics of isolated-photon plus jet production in pp collisions at a
centre-of-mass energy of 7 TeV has been studied with the ATLAS detector at the
LHC using an integrated luminosity of 37 pb-1. Measurements of isolated-photon
plus jet bin-averaged cross sections are presented as functions of photon
transverse energy, jet transverse momentum and jet rapidity. In addition, the
bin-averaged cross sections as functions of the difference between the
azimuthal angles of the photon and the jet, the photon--jet invariant mass and
the scattering angle in the photon--jet centre-of-mass frame have been
measured. Next-to-leading-order QCD calculations are compared to the
measurements and provide a good description of the data, except for the case of
the azimuthal opening angle.Comment: 33 pages plus author list (52 pages total), 18 figures, 7 tables,
  submitted to Nuclear Physics B, All figures including auxiliary figures are
  available at
  https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/STDM-2012-18
Feasibility of top quark measurements at LHCb and constraints on the
  large-$x$ gluon PDF

The forward LHCb acceptance opens interesting possibilities of studying
precision Standard Model hard processes in a kinematical region beyond the
reach of ATLAS and CMS. In this paper we perform a feasibility study for
cross-section measurements of top quark pairs with the LHCb detector, with an
analysis of signal and background rates for selected final states, and
determine the potential precision achievable at $\sqrt{s} =$ 7 and 14~TeV. We
then study the dependence of theoretical uncertainties on the pseudorapidity
distribution of top quarks produced in pair production at NLO, and observe that
a cross-section measurement at high pseudorapidity has enhanced sensitivity to
probe the high-$x$ gluon PDF as compared to measurements in the central-region.
Based on simulated pseudodata, the impact of a 14~TeV cross-section measurement
on the gluon PDF and charge asymmetry is quantified.Comment: 25 pages, 14 figures, 8 tables. Extended PDF analysis to include
  ABM11 5flv nlo. Added summary plots of LHCb cross-sections. Include shift of
  gluon PDF central value for CT10, NNPDF sets assuming different pseudodata
  values. Matches version to be published in JHE
Electroweak $ZZjj$ production in the Standard Model and beyond in the
  POWHEG-BOX V2

We present an implementation of electroweak $ZZjj$ production in the POWHEG
BOX V2 framework, an upgrade of the POWHEG BOX program which includes a number
of new features that are particularly helpful for high-multiplicity processes.
We consider leptonic and semi-leptonic decay modes of the Z bosons, and take
non-resonant contributions and spin correlations of the final-state particles
into account. In the case of decays to leptons, we also include interactions
beyond the Standard Model that arise from an effective Lagrangian which
includes CP conserving and violating operators up to dimension six. We find
that while leptonic distributions are very sensitive to anomalous couplings,
because of the small cross-section involved, these analyses are feasible only
after a high-luminosity upgrade of the LHC. We consider the cases of a 14 TeV,
33 TeV and 100 TeV machine and discuss the limits that can be placed on those
couplings for different luminosities.Comment: 19 pages, 18 figures,5 table
Observations of "Fresh" and Weathered Surfaces on Asteroid Pairs and
  Their Implications on the Rotational-Fission Mechanism

The rotational-fission of a rubble-pile asteroid can result in an "asteroid
pair", two un-bound asteroids sharing similar orbits. This mechanism might
exposes material that previously had never have been exposed to the weathering
conditions of space. Therefore, the surfaces of asteroid pairs offer the
opportunity to observe non-weathered fresh spectra. We report near-IR
spectroscopic observations of 31 asteroids in pairs. We analyze their spectral
slopes, 1 {\mu}m absorption band, taxonomy, and estimate the time elapsed since
their separation. Analyzing the 19 S-complex objects in our sample, we find two
fresh Q-type asteroids that are the first of their kind to be observed in the
main-belt over the full visible and near-IR range. This solidly demonstrates
that Q-type objects are not limited to the NEA population. The pairs in our
sample present a range of fresh and weathered surfaces with no clear evidence
for a correlation with the ages of the pairs. However, our sample includes old
pairs (1 to 2 My) that present low spectral slopes. This illustrates a
timescale of at least ~2 My before an object develops high spectral slope that
is typical for S-type asteroids.
  We discuss mechanisms that explain the existence of weathered pairs with
young dynamical ages and find that the "secondary fission" model (Jacobson &
Scheeres 2011) is the most robust with our observations since: 1) the secondary
members in our sample present fresh parameters that tend to be fresher than
their weathered primaries; 2) most of the fresh pairs in our sample have low
size ratios between the secondary and the primary; 3) 33% of the primaries in
our sample are fresh, similar to the prediction set by this model; 4) known
satellites orbit two of the pairs in our sample with low size ratio and fresh
surface; 5) there is no correlation between the weathering state and the
primary shape as predicted by other models.Comment: 19 pages, 17 figures, 4 tables. Accepted to Icaru
The Glashow resonance in neutrino-photon scattering

Reactions ${\nu_l}\gamma\rightarrow W^+l^-\,(l=e,\mu,\tau)$ near the
threshold $\sqrt{s}=m_W+m_l$ are analyzed. Two independent calculations of the
corresponding cross sections (straightforward calculations using the Standard
Electroweak Lagrangian and calculations in the framework of the parton model)
are compared. It is shown that the Standard Electroweak Theory strongly
suggests that these reactions proceed via the Glashow resonances. Accordingly,
a hypothesis that the on-shell $W$ bosons in the reactions
${\nu_l}\gamma\rightarrow$$W^+l^-$ are the Glashow resonances is put forward. A
role of these reactions for testing T symmetry at the IceCube Neutrino
Observatory is discussed. A model with T-violating Glashow resonances for
description of the distribution of the TeV-PeV neutrino events recently
observed by the IceCube Collaboration is presented.Comment: 25 pages, 11 figures. Typos corrected, minor changes, new references
  added. Accepted for publication in PL
Higgs-strahlung production process e^+ e^- \to Z h at the future Higgs
  factory in the Minimal Dilaton Model

We investigate the Higgs-strahlung production process e^+ e^- \to Z h at the
future Higgs factory such as TLEP by including radiative corrections in the
Minimal Dilaton Model (MDM), which extends the SM by one singlet scalar called
dilaton. We consider various theoretical and experimental constraints on the
model, and perform fits to the Higgs data taken from ATLAS, CMS and CDF+D0.
Then for the 1\sigma surviving samples, we calculate the MDM predictions on the
inclusive production rate \sigma(e^+e^-\to Zh) at the 240-GeV Higgs factory,
and also the signal rates of e^+e^-\to Zh with the Higgs boson decaying to
b\bar b and \gamma\gamma. We have following observations: (1) In the heavy
dilaton scenario, the deviation of \sigma(e^+e^-\to Zh) from its SM prediction
can vary from -15\% to 85\%, which mainly arises from the modification of the
tree-level hZZ coupling and also the radiative correction induced by possibly
large Higgs self-couplings. (2) The processes e^+e^-\to Zh at the Higgs factory
and pp\to hh at 14-TeV LHC are complementary in limiting the MDM parameter
space. Requiring the deviation of \sigma(e^+e^-\to Zh) from its SM prediction
to be less than 1\% and that of \sigma(p p \to h h) to be less than 50\%, \tan
\theta_S in the MDM will be limited to be -0.1<\tan\theta_S<0.3, and the
deviations of the signal rates are constrained to be |R_{b\bar b}|<2\% and
|R_{\gamma\gamma}|<7\%. Especially, the Higgs self-coupling normalized to its
SM prediction is now upper bounded by about 4. (3) In the light dilaton
scenario, the deviation of \sigma(e^+e^-\to Zh) may reach -7\%, and requiring
its size to be less than 1\% will result in 0<\tan\theta_S<0.1, and -10\% <
R_{b\bar b}, R_{\gamma\gamma} < 1\%.Comment: 18pages, 8 fiugres, References adde
Isolation of Flow and Nonflow Correlations by Two- and Four-Particle
  Cumulant Measurements of Azimuthal Harmonics in $\sqrt{s_{_{\rm NN}}} =$ 200
  GeV Au+Au Collisions

A data-driven method was applied to measurements of Au+Au collisions at
$\sqrt{s_{_{\rm NN}}} =$ 200 GeV made with the STAR detector at RHIC to isolate
pseudorapidity distance $\Delta\eta$-dependent and $\Delta\eta$-independent
correlations by using two- and four-particle azimuthal cumulant measurements.
We identified a component of the correlation that is $\Delta\eta$-independent,
which is likely dominated by anisotropic flow and flow fluctuations. It was
also found to be independent of $\eta$ within the measured range of
pseudorapidity $|\eta|<1$. The relative flow fluctuation was found to be $34\%
\pm 2\% (stat.) \pm 3\% (sys.)$ for particles of transverse momentum $p_{T}$
less than $2$ GeV/$c$. The $\Delta\eta$-dependent part may be attributed to
nonflow correlations, and is found to be $5\% \pm 2\% (sys.)$ relative to the
flow of the measured second harmonic cumulant at $|\Delta\eta| > 0.7$
A Trio of Dualities: Walls, Trees and Cascades

We study the RG flow of N=1 world-volume gauge theories of D3-brane probes on
certain singular Calabi-Yau threefolds. Taking the gauge theories out of
conformality by introducing fractional branes, we compute the NSVZ
beta-function and follow the subsequent RG flow in the cascading manner of
Klebanov-Strassler. We study the duality trees that blossom from various
Seiberg dualities and encode possible cascades. We observe the appearance of
duality walls, a finite limit energy scale in the UV beyond which the
dualization cascade cannot proceed. Diophantine equations of the Markov type
characterize the dual phases of these theories. We discuss how the
classification of Markov equations for different geometries into families
relates the RG flows of the corresponding gauge theories.Comment: 10 pages, 13 figures, Submitted to "Fortschritte der Physik" as part
  of the proceedings of the "36th International Symposium Ahrenshoop on the
  Theory of Elementary Particles," Berlin, August 26-30, 2003, and based on
  talks given by A. Hanany in Berlin and The University of Pennsylvannia,
  Philadelphi
Fluid Models for Kinetic Effects on Coherent Nonlinear Alfven Waves; 2, Numerical Solutions

The influence of various kinetic effects (e.g. Landau damping, diffusive and collisional dissipation, and finite Larmor radius terms) on the nonlinear evolution of finite amplitude Alfvenic wave trains in a finite-beta environment is systematically investigated using a novel, kinetic nonlinear Schrodinger (KNLS) equation. The dynamics of Alfven waves is sensitive to the sense of polarization as well as the angle of propagation with respect to the ambient magnetic field. Numerical solution for the case with Landau damping reveals the formation of dissipative structures, which are quasi-stationary, S-polarized directional (and rotational) discontinuities which self-organize from parallel propagating, linearly polarized waves. Parallel propagating circularly polarized packets evolve to a few circularly polarized Alfven harmonics on large scales. Stationary arc-polarized rotational discontinuities form from obliquely propagating waves. Collisional dissipation, even if weak, introduces enhanced wave damping when beta is very close to unity. Cyclotron motion effects on resonant particle interactions introduce cyclotron resonance into the nonlinear Alfven wave dynamics
The Baryon Density Through The (Cosmological) Ages

The light element abundances probe the baryon density of the universe within a few minutes of the Big Bang. Of these relics from the earliest universe, deuterium is the baryometer of choice. By comparing its primordial abundance inferred from observations with that predicted by Big Bang Nucleosynthesis (BBN), the early universe baryon density is derived. This is then compared to independent estimates of the baryon density several hundred thousand years after the Big Bang and at present, more than 10 billion years later. The excellent agreement among these values represents an impressive confirmation of the standard model of cosmology
Amp\`ere-Class Pulsed Field Emission from Carbon-Nanotube Cathodes in a
  Radiofrequency Resonator

Pulsed field emission from cold carbon-nanotube cathodes placed in a
radiofrequency resonant cavity was observed. The cathodes were located on the
backplate of a conventional $1+\frac{1}{2}$-cell resonant cavity operating at
1.3-GHz and resulted in the production of bunch train with maximum average
current close to 0.7 Amp\`ere. The measured Fowler-Nordheim characteristic,
transverse emittance, and pulse duration are presented and, when possible,
compared to numerical simulations. The implications of our results to
high-average-current electron sources are briefly discussed.Comment: 5 pages, 6 figures; submitted to Applied Physics Letter
Electroweak corrections to $Z$-boson hadroproduction at finite
  transverse momentum

We calculate the full one-loop electroweak radiative corrections, of ${\cal
O}(\alpha^2\alpha_s)$, to the cross section of single $Z$-boson inclusive
hadroproduction at finite transverse momentum ($p_T$). This includes the ${\cal
O}(\alpha)$ corrections to $Z+j$ production, the ${\cal O}(\alpha_s)$
corrections to $Z+\gamma$ production, and certain QCD-electroweak interference
contributions involving a single quark trace. We recover the QCD and purely
weak corrections and study the QED corrections and the QCD-electroweak
interference contributions for the first time. We also consider direct and
resolved photoproduction in elastic and inelastic scattering. We present $p_T$
and rapidity distributions for the experimental conditions at the Fermilab
Tevatron and the CERN LHC and assess the significance of the various
contributions.Comment: 31 pages, 11 figures; discussion enhanced, figures added, references
  added and updated; accepted for publication in Nucl. Phys.
Turbulent-laminar patterns in shear flows without walls

Turbulent-laminar intermittency, typically in the form of bands and spots, is
a ubiquitous feature of the route to turbulence in wall-bounded shear flows.
Here we study the idealised shear between stress-free boundaries driven by a
sinusoidal body force and demonstrate quantitative agreement between turbulence
in this flow and that found in the interior of plane Couette flow -- the region
excluding the boundary layers. Exploiting the absence of boundary layers, we
construct a model flow that uses only four Fourier modes in the shear direction
and yet robustly captures the range of spatiotemporal phenomena observed in
transition, from spot growth to turbulent bands and uniform turbulence. The
model substantially reduces the cost of simulating intermittent turbulent
structures while maintaining the essential physics and a direct connection to
the Navier-Stokes equations.
  We demonstrate the generic nature of this process by introducing stress-free
equivalent flows for plane Poiseuille and pipe flows which again capture the
turbulent-laminar structures seen in transition.Comment: 13 pages, 9 figure
A near-infrared interferometric survey of debris disc stars : III. First statistics based on 42 stars observed with CHARA/FLUOR

The authors thank the French National Research Agency (ANR) for financial support through contract ANR-2010 BLAN-0505-01 (EXOZODI). O.A. acknowledges financial support from the European Commission’s Sixth Framework Programme as a Marie Curie Intra-European Fellow and from an F.R.S.-FNRS Postdoctoral Fellowship during part(s) of this work.Context. Dust is expected to be ubiquitous in extrasolar planetary systems owing to the dynamical activity of minor bodies. Inner dust populations are, however, still poorly known because of the high contrast and small angular separation with respect to their host star, and yet, a proper characterisation of exozodiacal dust is mandatory for the design of future Earth-like planet imaging missions. Aims. We aim to determine the level of near-infrared exozodiacal dust emission around a sample of 42 nearby main sequence stars with spectral types ranging from A to K and to investigate its correlation with various stellar parameters and with the presence of cold dust belts. Methods. We use high-precision K-band visibilities obtained with the FLUOR interferometer on the shortest baseline of the CHARA array. The calibrated visibilities are compared with the expected visibility of the stellar photosphere to assess whether there is an additional, fully resolved circumstellar emission source. Results. Near-infrared circumstellar emission amounting to about 1% of the stellar flux is detected around 13 of our 42 target stars. Follow-up observations showed that one of them (eps Cep) is associated with a stellar companion, while another one was detected around what turned out to be a giant star (kap CrB). The remaining 11 excesses found around single main sequence stars are most probably associated with hot circumstellar dust, yielding an overall occurrence rate of 28+8-6 for our (biased) sample. We show that the occurrence rate of bright exozodiacal discs correlates with spectral type, K-band excesses being more frequent around A-type stars. It also correlates with the presence of detectable far-infrared excess emission in the case of solar-type stars. Conclusions. This study provides new insight into the phenomenon of bright exozodiacal discs, showing that hot dust populations are probably linked to outer dust reservoirs in the case of solar-type stars. For A-type stars, no clear conclusion can be made regarding the origin of the detected near-infrared excesses.Publisher PDFPeer reviewe
Characterization of low-mass, wide-separation substellar companions to stars in upper Scorpius : near-infrared photometry and spectroscopy

F.-R.L. is supported by a Research Fellowship from the Fonds de Recherche du Québec—Nature et Technologies. D.L. is supported in part through grants from the Natural Sciences and Engineering Research Council, Canada (NSERC), and from the Université de Montréal. Additional support for this work came from NSERC grants to R.J. Ch.H. acknowledges an ERC starting grant under the FP7 program of the European Union.We present new 0.9–2.45 μm spectroscopy (R ∼ 1000), and Y, J, H, Ks,L photometry, obtained at Gemini North, of three low-mass brown dwarf companions on wide orbits around young stars of the Upper Scorpius OB association: HIP 78530 B, [PGZ 2001] J161031.9-191305 B, and GSC 06214-00210 B. We use these data to assess the companions' spectral type, temperature, surface gravity, and mass, as well as the ability of the BT-SETTL and Drift-Phoenix atmosphere models to reproduce the spectral features of young substellar objects. For completeness, we also analyze the archival spectroscopy and photometry of the Upper Scorpius planetary mass companion 1RXS J160929.1-210524 b. Based on a comparison with model spectra we find that the companions, in the above order, have effective temperatures of 2700 ± 100, 2500 ± 200, 2300 ± 100, and 1700 ± 100 K. These temperatures are consistent with our inferred spectral types, respectively M7 β, M9 γ, M9 γ, and L4 γ, obtained from spectral indices and comparisons with templates. From bolometric luminosities estimated from atmosphere model spectra adjusted to our photometry, and using evolution models at 5–10 Myr, we estimate masses of 21–25, 28–70, 14–17, and 7–12 MJup, respectively. [PGZ 2001] J161031.9-191305 B appears significantly overluminous for its inferred temperature, which explains its higher mass estimate. Synthetic spectra based on the BT-Settl and Drift-Phoenix atmosphere models generally offer a good fit to our observed spectra, although our analysis has highlighted a few problems. For example, the best fits in the individual near-infrared bands occur at different model temperatures. Also, temperature estimates based on a comparison of the broadband magnitudes and colors of the companions to synthetic magnitudes from the models are systematically lower than the temperature estimates based on a comparison with synthetic spectra.Publisher PDFPeer reviewe