Fri·Mar 13, 2020Friday·March 13, 2020

1. 01*

   Nuclear level density of ${}^{69}$Zn from gamma gated particle spectrum and its implication on ${}^{68}$Zn(n, $\gamma$)${}^{69}$Zn capture cross-section

   Rajkumar Santra🇮🇳 · Balaram Dey🇮🇳 · Subinit Roy🇮🇳 · Md. S. R. Laskard · R. Palit🇮🇳 · H. Pai🇩🇪 · S. Rajbanshi · Sajad Alia · Saikat Bhattacharjee🇨🇦 · F. S. Babrad · Anjali Mukherjeec · S. Jadhavd and 3 other authors

   Evaporated $\alpha$-spectra have been measured in coincidence with low energy discrete $\gamma$-rays from residual nucleus ${}^{68}$Zn populated in the reaction ${}^{64}$Ni(${}^9$Be,$\alpha$n)${}^{68}$Zn at $E{(}^9$Be) = 30 MeV producing ${}^{73}$Ge compound nucleus. Low energy $\gamma$-gated $\alpha$-particle spectra, for the first time, have been used to extract the nuclear level density (NLD) for the intermediate ${}^{69}$Zn nucleus in the excitation energy range of E $\approx$ 5-20 MeV. The slope of NLD as a function of excitation energy for ${}^{69}$Zn matches nicely with the slope determined from RIPL estimates for NLD at low energies and the NLD from neutron resonance data. Extracted inverse NLD parameter (k = A/$\tilde{a}$) has been used to determine the nuclear level density parameter value $a$ at neutron separation energy $S_n$ for ${}^{69}$Zn. Total cross-section of ${}^{68}$Zn(n,$\gamma$) capture reaction as a function of neutron energy is then estimated employing the derived $a(S_n)$ in the reaction code TALYS. It is found that the estimated neutron capture cross-section agrees well with the available experimental data without any normalization. The present result indicates that experimentally derived nuclear level density parameter can constrain the statistical model description of astrophysical capture cross-section and optimize the uncertainties associated with the astrophysical reaction rate

   nucl-exPLB(2020)·10 citations
2. 02*

   A collision geometry-based 3D initial condition for relativistic heavy-ion collisions

   Chun Shen🇺🇸 · Sahr Alzhrani🇺🇸

   We present a simple way to construct 3D initial conditions for relativistic heavy-ion collisions based on the Glauber collision geometry. Local energy and momentum conservation conditions are imposed to set non-trivial constraints on our parameterizations of longitudinal profiles for the system's initial energy density and flow velocity. After calibrating parameters with charged hadron rapidity distributions in central Au+Au collisions, we test model predictions for particle rapidity distributions in d+Au and peripheral Au+Au collisions in the Beam Energy Scan (BES) program at Relativistic Heavy-Ion Collider (RHIC). Simulations and comparisons with measurements are also made for Pb+Pb collisions at Super Proton Synchrotron (SPS) energies. We demonstrate that elliptic flow measurements in heavy-ion collisions at $\sqrt{s}\sim 10$ GeV can set strong constraints on the dependence of Quark-Gluon Plasma shear viscosity on temperature and net baryon chemical potential.

   ↳ nucl-thhep-phnucl-exPRC(2020)·144 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.