Fri·Aug 22, 2014Friday·August 22, 2014

1. 01*

   Neutron-Proton Scattering in the Context of the $d^{\ast }$(2380) Resonance

   P. Adlarson · W. Augustyniak · W. Bardan · M. Bashkanov · F.S. Bergmann · M. Berłowski · H. Bhatt · M. Büscher · H. Calén · I. Ciepał · H. Clement · D. Coderre and 96 other authors

   New data on quasifree polarized neutron-proton scattering, in the region of the recently observed $d^{\ast }$ resonance structure, have been obtained by exclusive and kinematically complete high-statistics measurements with WASA at COSY. This paper details the determination of the beam polarization, checks of the quasifree character of the scattering process, on all obtained $A_y$ angular distributions and on the new partial-wave analysis, which includes the new data producing a resonance pole in the ${}^3{D}_3$-${}^3{G}_3$ coupled partial waves at ($2380\pm 10-i40\pm 5$) MeV -- in accordance with the $d^{\ast }$ dibaryon resonance hypothesis. The effect of the new partial-wave solution on the description of total and differential cross section data as well as specific combinations of spin-correlation and spin-transfer observables available from COSY-ANKE measurements at $T_d$ = 2.27 GeV is discussed.

   nucl-exhep-exPRC(2014)·104 citations
2. 02*

   Charged-to-neutral correlation at forward rapidity in Au+Au collisions at $\sqrt{s_{NN}}$=200 GeV

   STAR Collaboration: N. M. Abdelwahab · L. Adamczyk🇵🇱 · J. K. Adkins🇺🇸 · G. Agakishiev🇷🇺 · M. M. Aggarwal🇮🇳 · Z. Ahammed🇮🇳 · I. Alekseev🇷🇺 · J. Alford🇺🇸 · C. D. Anson🇺🇸 · A. Aparin🇷🇺 · D. Arkhipkin🇺🇸 · E. C. Aschenauer🇺🇸 and 339 other authors

   Event-by-event fluctuations of the ratio of inclusive charged to photon multiplicities at forward rapidity in Au+Au collision at $\sqrt{s_{NN}}$=200 GeV have been studied. Dominant contribution to such fluctuations is expected to come from correlated production of charged and neutral pions. We search for evidences of dynamical fluctuations of different physical origins. Observables constructed out of moments of multiplicities are used as measures of fluctuations. Mixed events and model calculations are used as baselines. Results are compared to the dynamical net-charge fluctuations measured in the same acceptance. A non-zero statistically significant signal of dynamical fluctuations is observed in excess to the model prediction when charged particles and photons are measured in the same acceptance. We find that, unlike dynamical net-charge fluctuation, charge-neutral fluctuation is not dominated by correlation due to particle decay. Results are compared to the expectations based on the generic production mechanism of pions due to isospin symmetry, for which no significant (<1%) deviation is observed.

   nucl-exhep-exPRC(2015)·8 citations
3. 03*

   Enhanced production of $\psi (2S)$ mesons in heavy ion collisions

   Sungtae Cho🇰🇷

   We study the production of a $\psi (2S)$ meson in heavy ion collisions. We evaluate Wigner functions for the $\psi (2S)$ meson using both Gaussian and Coulomb wave functions, and investigate the wave function dependence in the $\psi (2S)$ meson production by recombination of charm and anti-charm quarks. The enhanced transverse momentum distribution of $\psi (2S)$ mesons compared to that of $J/\psi$ mesons, originated from wave function distributions of the $\psi (2S)$ and $J/\psi$ meson in momentum space, provides a plausible explanation for the recent measurement of the nuclear modification factor ratio between the $\psi (2S)$ and $J/\psi$ meson.

   ↳ nucl-thhep-phnucl-exPRC(2015)·17 citations
4. 04*

   Systematic study of shell gaps in nuclei

   Qiuhong Mo🇨🇳 · Min Liu🇨🇳 · Ning Wang🇨🇳

   The nucleon separation energies and shell gaps in nuclei over the whole nuclear chart are systematically studied with eight global nuclear mass models. For unmeasured neutron-rich and super-heavy regions, the uncertainty of the predictions from these different mass models is still large. The latest version (WS4) of the Weizsäcker-Skyrme mass formula, in which the isospin dependence of model parameters is introduced into the macroscopic-microscopic approach inspired by the Skyrme energy-density functional, is found to be the most accurate one in the descriptions of nuclear masses, separation energies and shell gaps. Based on the predicted shell gaps in nuclei, the possible magic numbers in super-heavy nuclei region are investigated. In addition to the shell closures at $N=184,Z=114$, the sub-shell closures at around $N=178,Z=120$ could also play a role for the stability of super-heavy nuclei.

   ↳ nucl-thnucl-exPRC(2014)·36 citations
5. 05*

   Measurements of heavy-flavour production and azimuthal anisotropy in Pb--Pb collisions with the ALICE detector

   Andrea Dubla (for the ALICE Collaboration)🇳🇱

   Hadrons containing heavy quarks, i.e. charm or beauty, are unique probes of the properties of the hot and dense QCD medium produced in heavy-ion collisions. Due to their large masses, heavy quarks are produced at the initial stage of the collision, almost exclusively via hard partonic scattering processes. Therefore, they are expected to experience the full collision history propagating through the QCD medium losing energy via elastic and inelastic collisions with the medium constituents. The ALICE collaboration has measured the production of open heavy-flavour hadrons via their hadronic and semi-electronic decays at mid-rapidity and in the semi-muonic decay channel at \mbox{forward rapidity} in pp, p--Pb and Pb--Pb collisions. In this talk the latest results on the open \mbox{heavy-flavour nuclear modification factor, $R_{\mathrm{AA}}$, and elliptic flow, $v_2$, are presented}.

   ↳ hep-exnucl-ex2 citations
6. 06*

   Beta-decay Studies in N~Z Nuclei Using No-Core Configuration-Interaction Model

   Wojciech Satula🇵🇱 · Jacek Dobaczewski🇵🇱 · Maciej Konieczka🇵🇱

   The no-core configuration-interaction model based on the isospin- and angular-momentum projected density functional formalism is introduced. Two applications of the model are presented: (i) determination of spectra of 0+ states in 62Zn and (ii) determination of isospin-symmetry-breaking corrections to superallowed beta-decay between isobaric-analogue 0+ states in 38Ca and 38K. It is shown that, without readjusting a single parameter of the underlying Skyrme interaction, in all three nuclei, the model reproduces the 0+ spectra surprisingly well.

   ↳ nucl-thnucl-exJPS Conf.Proc.(2015)·7 citations
7. 07*

   Study of neutron-induced background and its effect on the search of 0$\nu \beta \beta$ decay in ${}^{124}\mathrm{Sn}$

   N. Dokania🇮🇳 · V. Singh🇮🇳 · S. Mathimalar🇮🇳 · C. Ghosh🇮🇳 · V. Nanal🇮🇳 · R.G. Pillay🇮🇳 · S. Pal🇮🇳 · K.G. Bhushan🇮🇳 · A. Shrivastava🇮🇳

   Neutron-induced background has been studied in various components of the TIN.TIN detector, which is under development for the search of Neutrinoless Double Beta Decay in ${}^{124}\mathrm{Sn}$. Fast neutron flux $\sim 10^{6}nc{m}^{-2}{s}^{-1}$ covering a broad energy range ($\sim 0.1$ to $\sim 18$~MeV) was generated using ${}^{9}Be(p,n{)}^{9}B$ reaction. In addition, reactions with quasi-monoenergetic neutrons were also studied using ${}^{7}Li(p,n{)}^{7}Be$ reaction. Among the different cryogenic support structures studied, Teflon is found to be preferable compared to Torlon as there is no high energy gamma background ($E_{\gamma }>$ 1 MeV). Contribution of neutron-induced reactions in ${}^{\mathrm{nat},124}$Sn from other Sn isotopes (A = 112 -- 122) in the energy region of interest, namely, around the $Q_{\beta \beta }$ of ${}^{124}\mathrm{Sn}$ ($E\sim$ 2.293 MeV), is also investigated.

   ↳ physics.ins-detnucl-exJINST(2014)·8 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.