Thu·Dec 24, 2015Thursday·December 24, 2015

1. 01*

   Multi-strange baryon production in p-Pb collisions at $\sqrt{s_{\mathbf{NN}}}=5.02$ TeV

   ALICE Collaboration

   The multi-strange baryon yields in Pb--Pb collisions have been shown to exhibit an enhancement relative to pp reactions. In this work, $\Xi$ and $\Omega$ production rates have been measured with the ALICE experiment as a function of transverse momentum, $p_{\mathrm{T}}$, in p-Pb collisions at a centre-of-mass energy of $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV. The results cover the kinematic ranges 0.6 GeV/$c<p_{\mathrm{T}}<$7.2 GeV/$c$ and 0.8 GeV/$c<p_{\mathrm{T}}<$ 5 GeV/$c$, for $\Xi$ and $\Omega$ respectively, in the common rapidity interval -0.5 $<y_{\mathrm{CMS}}<$ 0. Multi-strange baryons have been identified by reconstructing their weak decays into charged particles. The $p_{\mathrm{T}}$ spectra are analysed as a function of event charged-particle multiplicity, which in p-Pb collisions ranges over one order of magnitude and lies between those observed in pp and Pb-Pb collisions. The measured $p_{\mathrm{T}}$ distributions are compared to the expectations from a Blast-Wave model. The parameters which describe the production of lighter hadron species also describe the hyperon spectra in high multiplicity p-Pb. The yield of hyperons relative to charged pions is studied and compared with results from pp and Pb-Pb collisions. A statistical model is employed, which describes the change in the ratios with volume using a canonical suppression mechanism, in which the small volume causes a species-dependent relative reduction of hadron production. The calculations, in which the magnitude of the effect depends on the strangeness content, show good qualitative agreement with the data.

   nucl-exhep-exPLB(2016)·270 citations
2. 02*

   Nuclear structure of 140Te with N = 88: Structural symmetry and asymmetry in Te isotopes with respect to the double-shell closure Z = 50 and N = 82

   C.-B. Moon · P. Lee · C. S. Lee · A. Odahara · R. Lozeva · A. Yagi · F. Browne · S. Nishimura · P. Doornenbal · G. Lorusso · P.-A. Söderström · T. Sumikama and 33 other authors

   We study for the first time the internal structure of 140Te through the beta-delayed gamma-ray spectroscopy of 140Sb. The very neutron-rich 140Sb, Z = 51 and N = 89, ions were produced by the in-flight fission of 238U beam on a 9Be target at 345 MeV per nucleon at the Radioactive Ion Beam Factory, RIKEN. The half-life and spin-parity of 140Sb are reported as 124(30) ms and (4-), respectively. In addition to the excited states of 140Te produced by the beta-decay branch, the beta-delayed one-neutron and two-neutron emission branches were also established. By identifying the first 2+ and 4+ excited states of 140Te, we found that Te isotopes persist their vibrator character with E(4+)/E(2+) = 2. We discuss the distinctive features manifest in this region, such as valence neutron symmetry and asymmetry, revealed in pairs of isotopes with the same neutron holes and particles with respect to N = 82.

   nucl-exPRC(2017)·36 citations
3. 03*

   Muon capture on light isotopes in Double Chooz

   Double Chooz collaboration: Y. Abe🇯🇵 · T. Abrahão🇧🇷 · H. Almazan🇩🇪 · C. Alt🇩🇪 · S. Appel🇩🇪 · J.C. Barriere🇫🇷 · E. Baussan🇫🇷 · I. Bekman🇩🇪 · M. Bergevin🇺🇸 · T.J.C. Bezerra🇯🇵 · L. Bezrukov🇷🇺 · E. Blucher🇺🇸 and 134 other authors

   Using the Double Chooz detector, designed to measure the neutrino mixing angle ${\theta }_{13}$, the products of ${\mu }^{-}$ capture on ${}^{12}$C, ${}^{13}$C, ${}^{14}$N and ${}^{16}$O have been measured. Over a period of 489.5 days, $2.3\times 10^6$ stopping cosmic ${\mu }^{-}$ have been collected, of which $1.8\times 10^5$ captured on carbon, nitrogen, or oxygen nuclei in the inner detector scintillator or acrylic vessels. The resulting isotopes were tagged using prompt neutron emission (when applicable), the subsequent beta decays, and, in some cases, $\beta$-delayed neutrons. The most precise measurement of the rate of ${}^{12}\mathrm{C}({\mu }^{-},\nu {)}^{12}\mathrm{B}$ to date is reported: $6.57_{-0.21}^{+0.11}\times 10^3{\mathrm{s}}^{-1}$, or $(17.35_{-0.59}^{+0.35})\%$ of nuclear captures. By tagging excited states emitting gammas, the ground state transition rate to ${}^{12}$B has been determined to be $5.68_{-0.23}^{+0.14}\times 10^3{\mathrm{s}}^{-1}$. The heretofore unobserved reactions ${}^{12}\mathrm{C}({\mu }^{-},\nu \alpha {)}^8\mathrm{Li}$, ${}^{13}\mathrm{C}({\mu }^{-},\nu \mathrm{n}\alpha {)}^8\mathrm{Li}$, and ${}^{13}\mathrm{C}({\mu }^{-},\nu \mathrm{n}{)}^{12}\mathrm{B}$ are measured. Further, a population of $\beta$n decays following stopping muons is identified with $5.5\sigma$ significance. Statistics limit our ability to identify these decays definitively. Assuming negligible production of ${}^8$He, the reaction ${}^{13}\mathrm{C}({\mu }^{-},\nu \alpha {)}^9\mathrm{Li}$ is found to be present at the $2.7\sigma$ level. Limits are set on a variety of other processes.

   nucl-exhep-exphysics.ins-detPRC(2016)·19 citations
4. 04*

   Antineutrino flux and spectrum calculation for spent nuclear fuel for the Daya Bay antineutrino experiment

   X.B. Ma🇨🇳 · Y.F. Zhao🇨🇳 · Y.X. Chen🇨🇳 · W.L. Zhong🇨🇳 · F.P. An🇨🇳

   Spent nuclear fuel (SNF) antineutrino flux is an important source of uncertainties for a reactor neutrino flux prediction. However, if one want to determine the contribution of spent fuel, many data are needed, such as the amount of spent fuel in the pool, the time after discharged from the reactor core, the burnup of each assembly, and the antineutrino spectrum of the isotopes in the spend fuel. A method to calculate the contribution of SNF is proposed in this study. In this method, reactor simulation code verified by experiment have been used to simulate the fuel depletion by taking into account more than 2000 isotopes and fission products, the quantity of SNF in each six spend fuel pool, and the antineutrino spectrum of SNF varying with time after SNF discharged from core. Results show that the contribution of SNF to the total antineutrino flux is about 0.26%~0.34%, and the shutdown impact is about 20%. The SNF spectrum would distort the softer part of antineutrino spectra, and the maximum contribution from SNF is about 3.0%, but there is 18\% difference between line evaluate method and under evaluate method. In addition, non-equilibrium effects are also discussed, and the results are compatible with theirs considering the uncertainties.

   ↳ physics.ins-dethep-exnucl-exNPA(2017)·9 citations
5. 05*

   Multiplicity fluctuations of net protons on the hydrodynamic freeze-out surface

   Lijia Jiang🇨🇳 · Pengfei Li🇨🇳 · Huichao Song (Peking U.)🇨🇳

   This proceeding briefly summarizes our recent work on calculating the correlated fluctuations of net protons on the hydrodynamic freeze-out surface near the QCD critical point. For both Poisson and Binomial baselines, our calculations could roughly reproduce the energy dependent cumulant $C_4$ and $\kappa {\sigma }^2$ of net protons, but always over-predict $C_2$ and $C_3$ due to the positive contributions from the static critical fluctuations.

   ↳ nucl-thnucl-exNPA(2016)·20 citations
6. 06*

   Proceedings of the third French-Ukrainian workshop on the instrumentation developments for HEP

   F. Alessio · S.Ya. Barsuk · L. Berge · O.A. Bezshyyko · R.S. Boiko · I. Chaikovska · M. Chapellier · G. Charles · A. Chaus · R. Chehab · D.M. Chernyak · N. Coron and 61 other authors

   The reports collected in these proceedings have been presented in the third French-Ukrainian workshop on the instrumentation developments for high-energy physics held at LAL, Orsay on October 15-16. The workshop was conducted in the scope of the IDEATE International Associated Laboratory (LIA). Joint developments between French and Ukrainian laboratories and universities as well as new proposals have been discussed. The main topics of the papers presented in the Proceedings are developments for accelerator and beam monitoring, detector developments, joint developments for large-scale high-energy and astroparticle physics projects, medical applications.

   ↳ physics.ins-dethep-exnucl-ex3 citations
7. 07*

   J/$\psi$ and $\psi (2S)$ measurement in p+p collisions at $\sqrt{s}=$ 200 and 500 GeV with the STAR experiment

   Barbara Trzeciak (for the STAR Collaboration)🇨🇿

   In this paper, results on the J/psi cross section and polarization measured via the dielectron decay channel at mid-rapidity in p+p collisions at 200 and 500 GeV in the STAR experiment are discussed. Also, first measurements of the J/psi production as a function of the charged-particle multiplicity density and of psi(2S) to J/psi ratio at 500 GeV are reported.

   ↳ hep-exnucl-exJ.Phys.Conf.Ser.(2016)·14 citations
8. 08*

   Generalization of the model-independent Laurent-Pietarinen single-channel pole-extraction formalism to multiple channels

   Alfred Svarc🇭🇷 · Mirza Hadzimehmedovic🇧🇦 · Hedim Osmanovic🇧🇦 · Jugoslav Stahov🇧🇦 · Lothar Tiator🇩🇪 · Ron L. Workman🇺🇸

   A method to extract resonance pole information from single-channel partial-wave amplitudes based on a Laurent (Mittag-Leffler) expansion and conformal mapping techniques has recently been developed. This method has been applied to a number of reactions and provides a model-independent extraction procedure which is particularly useful in cases where a set of amplitudes is available only at descrete energies. This method has been generalized and applied to the case of a multi-channel fit, where several sets of amplitudes are analysed simultaneously. The importance of unitarity constraints is discussed. The final result provides a powerful, model-independent tool for analyzing partial-wave amplitudes of coupled or connected channels based entirely on the concepts of analyticity and unitarity.

   ↳ nucl-thnucl-exPLB(2016)·19 citations
9. 09*

   J/$\psi$ polarization measurements in p+p collisions at $\sqrt{s}$ = 200 and 500 GeV with the STAR experiment

   Barbara Trzeciak (for the STAR Collaboration)🇨🇿

   In these proceedings, measurements of J/psi polarization in p+p collisions at 200 and 500 GeV via the dielectron decay channel at mid-rapidity with the STAR experiment are discussed. At 200 GeV the polarization parameter, ${\lambda }_{\theta }$, related to the polar anisotropy is obtained in the helicity frame as a function of transverse momentum, 2 < $p_T$ < 6 GeV/c, and compared to different model predictions. A new J/psi polarization measurement at 500 GeV extends the previous analysis to a wide transverse momentum range of 5 < $p_T$ < 16 GeV/c. Also, the polarization parameter related to the azimuthal anisotropy, ${\lambda }_{\varphi }$, is extracted in addition to ${\lambda }_{\theta }$, in two reference frames: the helicity and Collins-Soper frames. This allows for the frame invariant parameter calculation vs $p_T$ in these two frames.

   ↳ hep-exnucl-exPoS(2015)·0 citations
10. 10*

    Double vector meson production in $\gamma \gamma$ interactions at hadronic colliders

    V. P. Goncalves🇧🇷 · B. D. Moreira🇧🇷 · F. S. Navarra🇧🇷

    In this paper we revisit the double vector meson production in $\gamma \gamma$ interactions at heavy ion collisions and present, by the first time, predictions for the $\rho \rho$ and $J/\Psi J/\Psi$ production in proton -- nucleus and proton -- proton collisions. In order to obtain realistic predictions for rapidity distributions and total cross sections for the double vector production in ultra peripheral hadronic collisions we take into account of the description of $\gamma \gamma \to VV$ cross section at low energies as well as its behaviour at large energies, associated to the gluonic interaction between the color dipoles. Our results demonstrate that the double $\rho$ production is dominated by the low energy behaviour of the $\gamma \gamma \to VV$ cross section. In contrast, for the double $J/\Psi$ production, the contribution associated to the description of the QCD dynamics at high energies contributes significantly, mainly in $pp$ collisions. Predictions for the RHIC, LHC, FCC and CEPC - SPPC energies are shown.

    ↳ hep-phhep-exnucl-exnucl-thEPJC(2016)·24 citations
11. 11*

    Heavy-flavour transport: from large to small systems

    A. Beraudo🇮🇹 · A. De Pace🇮🇹 · M. Monteno🇮🇹 · M. Nardi🇮🇹 · F. Prino🇮🇹

    Predictions for heavy-flavour production in relativistic heavy-ion experiments provided by the POWLANG transport setup, including now also an in-medium hadronization model, are displayed, After showing some representative findings for the Au-Au and Pb-Pb cases, a special focus will be devoted to the results obtained in the small systems formed in proton(deuteron)-nucleus collisions, where recent experimental data suggest the possible formation of a medium featuring a collective behaviour.

    ↳ hep-phnucl-exnucl-thNPA(2016)·1 citation
12. 12*

    Shielding concepts for low-background proportional counter arrays in surface laboratories

    Craig E. Aalseth🇺🇸 · Paul H. Humble · Emily K. Mace · John L. Orrell🇺🇸 · Allen Seifert · Richard M. Williams

    Development of ultra low background gas proportional counters has made the contribution from naturally occurring radioactive isotopes -- primarily $\alpha$ and $\beta$ activity in the uranium and thorium decay chains -- inconsequential to instrumental sensitivity levels when measurements are performed in above ground surface laboratories. Simple lead shielding is enough to mitigate against gamma rays as gas proportional counters are already relatively insensitive to naturally occurring gamma radiation. The dominant background in these surface laboratory measurements using ultra low background gas proportional counters is due to cosmic ray generated muons, neutrons, and protons. Studies of measurements with ultra low background gas proportional counters in surface and underground laboratories as well as radiation transport Monte Carlo simulations suggest a preferred conceptual design to achieve the highest possible sensitivity from an array of low background gas proportional counters when operated in a surface laboratory. The basis for a low background gas proportional counter array and the preferred shielding configuration is reported, especially in relation to measurements of radioactive gases having low energy decays such as ${}^{37}$Ar.

    ↳ physics.ins-detnucl-exAppl.Radiat.Isot.(2016)·0 citations

* 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.