Nuclear Experiment·nucl-ex
12 papers—9 primary·3 cross-listed·reconstructed*
R. Robinson🇺🇸 · M. Thoennessen🇺🇸
Currently, thirty-eight tantalum, thirty-eight rhenium, thirty-nine osmium, and thirty-eight iridium, isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.
Jorge A. Robles (for the CMS collaboration)
The unprecedented centre-of-mass energy available at the LHC offers unique opportunities for studying the properties of the strongly-interacting QCD matter created in PbPb collisions at extreme temperatures and very low parton momentum fractions. With its high precision, large acceptance for tracking and calorimetry, and a trigger scheme that allows analysis of each minimum bias PbPb event, CMS is fully equipped to measure dimuons in the high multiplicity environment of nucleus-nucleus collisions. Such probes are especially relevant for these studies since they are produced at early times and propagate through the medium, mapping its evolution. Inclusive and differential measurements of the Z boson yield will be shown, establishing that no modification is observed with respect to theoretical next-to-leading order pQCD calculations. The validity of the Glauber scaling for perturbative cross sections in nucleus-nucleus collisions at the LHC is confirmed. In addition, the status of the quarkonia measurements (primary and secondary J/\psi, and the 3 Upsilon states) will be reviewed, both in pp and in PbPb collisions.
Jorge A. Robles (for the CMS collaboration)
The unprecedented center-of-mass energy available at the LHC offers unique opportunities for studying the properties of the strongly-interacting QCD matter created in PbPb collisions at extreme temperatures and very low parton momentum fractions. Electroweak boson production is an important benchmark process at hadron colliders. Precise measurements of Z production in heavy-ion collisions can help to constrain nuclear PDFs as well as serve as a standard candle of the initial state in PbPb collisions at the LHC energies. The inclusive and differential measurements of the Z boson yield in the muon decay channel will be presented, establishing that no modification is observed with respect to next-to-leading order pQCD calculations, scaled by the number of incoherent nucleon-nucleon collisions. The status of the Z measurement in the electron decay channel, as well as the first observation of W \rightarrow \mu {\nu} in heavy ion collisions will be given. The heavy-ion results will be presented in the context of those obtained in pp collisions with the CMS detector.
Chris Perkins (for the STAR Collaboration)🇺🇸
Measurements of azimuthal differences between forward di-pions are sensitive to the low- gluon content of the proton and provide the best opportunity to probe for gluon saturation in nuclei. Previously reported analyses have shown that the gluon saturation regime may have been reached at STAR by looking at forward di-pions in d+Au collisions. Further insight into the uncorrelated pedestal below the near-side and away-side peaks in azimuthal correlations may be provided by differentiating between d+Au and p+Au collisions, by tagging on intact neutrons in the deuteron beam in d+Au collisions. Comparisons to recent theories indicate that multi-parton interactions play a more significant role in d+Au collisions than p+Au collisions and offer a unique opportunity to study correlations between leading partons inside nucleons. The general features found for the peaks in forward di-pion azimuthal correlations in d+Au collisions are also present in p+Au collisions.
Measuring the single transverse spin asymmetry for large Drell-Yan production provides the most robust test of our current theoretical understanding of transverse proton spin structure. This includes a measurement of the predicted sign change of the Sivers function in comparison to that found in SIDIS data. The first year of a feasibility test has been completed to define the requirements for measuring large Drell-Yan production at RHIC. The impact of colliding beams at a third IR at RHIC was found to be negligible and a rich jet-triggered data sample was acquired by AnDY in RHIC Run 11. Plans for subsequent runs are currently underway.
M. J. Tannenbaum (for the PHENIX Collaboration)🇺🇸
The method of measuring , the ratio of the away-parton transverse momentum, , to the trigger-parton transverse momentum, , using two-particle correlations at RHIC, will be reviewed. This measurement is simply related to the two new variables introduced at LHC for the di-jet fractional transverse momentum imbalance: ATLAS ; and CMS . Results from two-particle correlations at RHIC for in p-p and A+A collisions will be reviewed and new results will be presented and compared to LHC results. The importance of comparing any effect in A+A collisions to the same effect effect in p-p collisions will be illustrated and emphasized.
SNO Collaboration: B. Aharmim🇨🇦 · S. N. Ahmed🇨🇦 · A. E. Anthony🇺🇸 · N. Barros🇵🇹 · E. W. Beier🇺🇸 · A. Bellerive🇨🇦 · B. Beltran🇨🇦 · M. Bergevin🇺🇸 · S. D. Biller🇬🇧 · K. Boudjemline🇨🇦 · M. G. Boulay🇨🇦 · B. Cai🇨🇦 and 111 other authors
We report results from a combined analysis of solar neutrino data from all phases of the Sudbury Neutrino Observatory. By exploiting particle identification information obtained from the proportional counters installed during the third phase, this analysis improved background rejection in that phase of the experiment. The combined analysis resulted in a total flux of active neutrino flavors from 8B decays in the Sun of (5.25 \pm 0.16(stat.)+0.11-0.13(syst.))\times10^6 cm^{-2}s^{-1}. A two-flavor neutrino oscillation analysis yielded \Deltam^2_{21} = (5.6^{+1.9}_{-1.4})\times10^{-5} eV^2 and tan^2{\theta}_{12}= 0.427^{+0.033}_{-0.029}. A three-flavor neutrino oscillation analysis combining this result with results of all other solar neutrino experiments and the KamLAND experiment yielded \Deltam^2_{21} = (7.41^{+0.21}_{-0.19})\times10^{-5} eV^2, tan^2{\theta}_{12} = 0.446^{+0.030}_{-0.029}, and sin^2{\theta}_{13} = (2.5^{+1.8}_{-1.5})\times10^{-2}. This implied an upper bound of sin^2{\theta}_{13} < 0.053 at the 95% confidence level (C.L.).
Zhenwei Yang🇨🇳 · Mingming Ding🇩🇪 · Shaomin Chen🇨🇳 · Zhe Wang🇨🇳 · Feng Zhang🇨🇳 · Yuanning Gao🇨🇳
Knowledge of - differential cross sections for energy below several tens of MeV scale is believed to be crucial in understanding Supernova physics. In a segmented detector at Spallation Neutrino Source, energy reconstructed from the electron range measurement is strongly affected because of both multiple scattering and electromagnetic showers occurring along the electron passage in target materials. In order to estimate the effect, a simulation study has been performed with a cube block model assuming a perfect tracking precision. The distortion of energy spectrum is observed to be proportional to the atomic number of target material. Feasibility of unfolding the distorted energy spectrum is studied for both Fe and Pb cases. Evaluation of statistical accuracy attainable is therefore provided for a segmented detector.
V. V. Belaga🇷🇺 · A. A. Benjaza · V. V. Rusakova🇷🇺 · J. A. Salamov · G. M. Chernov🇷🇺
The transverse-momentum distributions and correlation characteristics of relativistic particles from the coherent dissociation of a carbon nucleus into three particles at 4.5 GeV/ are studied in lead-enriched emulsion. Comparative analysis of data obtained in ordinary and lead-enriched emulsion stacks is performed. It is shown that the statistical model of rapid fragmentation does not describe the momentum and correlation characteristics of a particles in the rest frame of the carbon nucleus. The estimated decay temperature of C is weakly dependent on the target atomic mass. It is shown that the carbon nucleus undergoing fragmentation acquires angular momentum in the collision.
Fluctuations of conserved quantities are predicted to be sensitive to the correlation length and connected to the thermodynamic susceptibility. Thus, moments of net-baryon, net-charge and net-strangeness have been extensively studied theoretically and experimentally to explore phase structure and bulk properties of QCD matters created in heavy ion collision experiment. As the moments analysis is statistics hungry study, the error estimation is crucial to extract physics information from the limited experimental data. In this paper, we will derive the limit distributions and error formula based on Delta theorem in statistics for various order moments used in the experimental data analysis. The Monte Carlo simulation is also applied to test the error formula.
Ron L. Workman🇺🇸 · William J. Briscoe🇺🇸 · Mark W. Paris🇺🇸 · Igor I. Strakovsky (GWU)🇺🇸
Energy-dependent and single-energy fits to the existing pion photoproduction database have been updated to cover the region from threshold to 2.7 GeV in the laboratory photon energy. Revised resonance photo-decay couplings have been extracted and compared to previous determinations. The influence of recent measurements is displayed. Remaining problems and future approaches are discussed.
V. Rebyakova (SPbSTU)🇷🇺 · M. Strikman (PSU)🇺🇸 · M. Zhalov (PNPI)🇷🇺
We present predictions for the J/psi and rho meson production in the heavy ion ultraperipheral collisions (UPC) for the current energy 2.76 TeV at the LHC. Both total cross sections and cross sections with the neutron emission from one or both nuclei are presented. We also analyse the RHIC rho meson photoproduction data and emphasize importance of these data to test the current model for nucleus break up in UPC.
* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.