Tue·Sep 16, 2014Tuesday·September 16, 2014

1. 01*

   Azimuthally integrated HBT parameters for charged pions in nucleus-nucleus interactions versus collision energy

   V.A. Okorokov (National Research Nuclear University "MEPhI")🇷🇺

   In the paper energy dependence of space-time extent of emission region obtained from Bose - Einstein correlations is studied for charged pions in various ion collisions for all experimentally available energies. There is no dramatic change of HBT parameters with increasing of collision energy per nucleon-nucleon pair, $\sqrt{s_{NN}}$, in domain of energies $\sqrt{s_{NN}}\ge 5$ GeV. Energy dependence of estimations for emission duration is almost flat for all energy domain under study within large error bars. Analytic function is suggested for smooth approximation of energy dependence of main HBT parameters. Fit curves demonstrate reasonable agreement with experimental data for most HBT parameters in energy domain $\sqrt{s_{NN}}\ge 5$ GeV. Estimations of some observables are obtained for energies of the LHC and FCC project.

   nucl-exhep-phAdv.High Energy Phys.(2015)·10 citations
2. 02*

   Reconstructed primary fragments and symmetry energy, temperature and density of the fragmenting source in ${}^{64}$Zn + ${}^{112}$Sn at 40 MeV/nucleon

   X. Liu · W. Lin🇨🇳 · R. Wada · M. Huang🇺🇸 · S. Zhang🇨🇳 · P. Ren🇨🇳 · Z. Chen🇨🇳 · J. Wang🇺🇸 · G. Q. Xiao🇨🇳 · R. Han · J. Liu🇨🇳 · F. Shi🇨🇳 and 8 other authors

   Symmetry energy, temperature and density at the time of the intermediate mass fragment formation are determined in a self-consistent manner, using the experimentally reconstructed primary hot isotope yields and anti-symmetrized molecular dynamics (AMD) simulations. The yields of primary hot fragments are experimentally reconstructed for multifragmentation events in the reaction system ${}^{64}$Zn + ${}^{112}$Sn at 40 MeV/nucleon. Using the reconstructed hot isotope yields and an improved method, based on the modified Fisher model, symmetry energy values relative to the apparent temperature, $a_{sym}/T$, are extracted. The extracted values are compared with those of the AMD simulations, extracted in the same way as that for the experiment, with the Gogny interaction with three different density-dependent symmetry energy terms. $a_{sym}/T$ values change according to the density-dependent symmetry energy terms used. Using this relation, the density of the fragmenting system is extracted first. Then symmetry energy and apparent temperature are determined in a self consistent manner in the AMD model simulations. Comparing the calculated $a_{sym}/T$ values and those of the experimental values from the reconstructed yields, $\rho /{\rho }_0=0.65\pm 0.02$, $a_{sym}=23.1\pm 0.6$ MeV and $T=5.0\pm 0.4$ MeV are evaluated for the fragmenting system experimentally observed in the reaction studied.

   nucl-exnucl-thNPA(2015)·15 citations
3. 03*

   Measurement of Coherent Production of ${\pi }^{\pm }$ in Neutrino and Anti-Neutrino Beams on Carbon from $E_{\nu }$ of $1.5$ to $20$ GeV

   A. Higuera🇺🇸 · A. Mislivec🇺🇸 · L. Aliaga🇺🇸 · O. Altinok🇺🇸 · A. Bercellie🇺🇸 · M. Betancourt🇺🇸 · A. Bodek🇺🇸 · A. Bravar🇨🇭 · W.K. Brooks🇨🇱 · H. Budd🇺🇸 · A. Butkevich🇷🇺 · M.F. Carneiro🇧🇷 and 60 other authors

   Neutrino-induced coherent charged pion production on nuclei, ${\stackrel{(-)}{\nu }}_{\mu }A\to {\mu }^{\pm }{\pi }^{\mp }A$ is a rare, inelastic interaction in which a small squared four-momentum $|t|$ is transferred to the recoil nucleus leaving it intact in the reaction. In the scintillator tracker of MINERvA, we remove events with evidence of particles from nuclear breakup and reconstruct $|t|$ from the final state pion and muon. We select low $|t|$ events to isolate a sample rich in coherent candidates. By selecting low $|t|$ events we produce a model-independent measurement of the differential cross section for coherent scattering of neutrinos and anti-neutrinos on carbon. We find poor agreement with the predicted kinematics in neutrino generators used by current oscillation experiments.

   ↳ hep-exnucl-exPRL(2014)·144 citations
4. 04*

   Shell model and deformed shell model spectroscopy of ${}^{62}$Ga

   P.C. Srivastava🇮🇳 · R. Sahu🇮🇳 · V.K.B. Kota🇮🇳

   In the present work we have reported comprehensive analysis of recently available experimental data [H.M. David et al., Phys. Lett. B {\bf 726}, 665 (2013)] for high-spin states up to $17^{+}$ with $T=0$ in the odd-odd $N=Z$ nucleus ${}^{62}$Ga using shell model calculations within the full $f_{5/2}p{g}_{9/2}$ model space and deformed shell model based on Hartee-Fock intrinsic states in the same space. The calculations have been performed using jj44b effective interaction developed recently by B.A. Brown and A.F. Lisetskiy for this model space. The results obtained with the two models are similar and they are in reasonable agreement with experimental data. In addition to the $T=0$ and $T=1$ energy bands, band crossings and electromagnetic transition probabilities, we have also calculated the pairing energy in shell model and all these compare well with the available theoretical results.

   ↳ nucl-thnucl-exEPJA(2015)·14 citations
5. 05*

   Quarkonia production in proton-lead collisions at LHCb

   Yiming Li🇨🇳

   The production of $J/\psi$ and ${\rm Y}$ mesons decaying into dimuon final state is studied at the LHCb experiment, with rapidity in the range of (1.5, 4.0) or (-5.0, -2.5) in proton-lead collisions at a nucleon-nucleon centre-of-mass energy $\sqrt{s_{NN}}$ = 5 TeV, based on a data sample corresponding to an integrated luminosity of 1.6 /fb. The nuclear modification factor and forward-backward production ratio are determined for prompt $J/\psi$, $J/\psi$ from b-hadron decay and ${\rm Y}(1S)$ mesons in study of the cold nuclear matter effects.

   ↳ hep-exnucl-ex0 citations
6. 06*

   Measurement of D-meson production in pp, p-Pb and Pb-Pb collisions with ALICE at the LHC

   A. Rossi · for ALICE Collaboration

   Heavy quarks, i.e. charm and beauty, are considered calibrated probes for the strongly interacting deconfined medium (Quark Gluon Plasma, QGP) formed in heavy-ion collisions. Produced in hard scattering processes in the initial stages of the collision, they interact with the medium, lose energy and, depending on the coupling strength to the medium, take part in the collective motion of the QCD matter. ALICE measured the production of ${\mathrm{D}}^0$, ${\mathrm{D}}^{\ast +}$, ${\mathrm{D}}^{+}$ and ${\mathrm{D}}_{\mathrm{s}}$ mesons at central rapidity in pp, p-Pb and Pb-Pb collisions at the LHC. The study of the modification of the transverse momentum differential yields of charm particles in Pb-Pb collisions with respect to pp collisions, quantified by the nuclear modification factor ($R_{\mathrm{AA}}$), can unravel details of the energy loss mechanism, such as its dependence on the quark mass and on the path length the parton travels through the medium. A similar comparison between pp and p-Pb collision data ($R_{\mathrm{pPb}}$) is fundamental to disentangle effects related to the presence of the hot medium from cold nuclear matter effects. The degree of thermalization and coupling to the medium is investigated in semi-peripheral Pb-Pb collisions by measuring the elliptic flow coefficient ($v_2$) at low pt. At high pt, $v_2$ is sensitive to the path-length dependence of the energy loss. Results on the transverse momentum and centrality dependence of the D-meson elliptic flow and $R_{AA}$ will be presented. The comparison with the $R_{\mathrm{AA}}$ of non-prompt $J/\psi$ from B-meson decays measured with CMS will be discussed. The preliminary results on D-meson $R_{\mathrm{pPb}}$ and the dependence of D-meson yields on rapidity in p-Pb collisions will be shown. As an outlook, the analysis and the preliminary results on the azimuthal correlations of D mesons and charged hadrons in pp collisions will be described.

   ↳ hep-exnucl-exNPA(2014)·5 citations
7. 07*

   Ingredients of nuclear matrix element for two-neutrino double-beta decay of 48Ca

   Y. Iwata🇯🇵 · N. Shimizu🇯🇵 · Y. Utsuno🇯🇵 · M. Honma🇯🇵 · T. Abe🇯🇵 · T. Otsuka🇯🇵

   Large-scale shell model calculations including two major shells are carried out, and the ingredients of nuclear matrix element for two-neutrino double beta decay are investigated. Based on the comparison between the shell model calculations accounting only for one major shell ($pf$-shell) and those for two major shells ($sdpf$-shell), the effect due to the excitation across the two major shells is quantitatively evaluated.

   ↳ nucl-thnucl-exJPS Conf.Proc.(2015)·14 citations
8. 08*

   Measurements of hadron production in p-Pb collisions at LHCf

   Gaku Mitsuka🇮🇹

   The transverse momentum distribution for inclusive neutral pions in very forward rapidity region has been measured with the LHCf detector in p-Pb collisions at nucleon-nucleon center-of-mass energies of $\sqrt{s_{NN}}$ = 5.02 TeV at the LHC. The transverse momentum spectra obtained in p-Pb collisions show a strong suppression of the production of neutral pions relative to the spectra in p-p collisions at $\sqrt{s}$ = 5.02 TeV. The nuclear modification factor is about 0.1-0.4, which overall agrees with the predictions of several hadronic interaction Monte Carlo simulations. Furthermore the recent results on the inclusive energy spectra of forward neutrons in p-p collisions at $\sqrt{s}$ = 7 TeV will be discussed.

   ↳ hep-exnucl-ex0 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.