Nuclear Theory·nucl-th

Wednesday·May 30, 2018

7 papers—6 primary·1 cross-listed

01
Bulk viscosity coefficient of hadronic matter
Sabyasachi Ghosh🇮🇳 · Sandeep Chatterjee🇮🇳 · Bedangadas Mohanty🇮🇳
The bulk viscosity coefficient of hadronic matter has been estimated in this present work, where the thermodynamical equilibrium quantity like speed of sound in the medium has been obtained by using standard hadron resonance gas model. Whereas, the non-equilibrium quantity like thermal widths of medium constituents have been calculated in the framework field theory at finite temperature. Our values of bulk viscosity coefficient are in agreement with some earlier estimations.
nucl-thhep-phnucl-exSpringer Proc.Phys.(2018)·0 citations
02
Sensitivity study of experimental measures for the nuclear liquid-gas phase transition in the statistical multifragmentation model
W. Lin · P. Ren · H. Zheng · X. Liu · M. Huang · R. Wada · G. Qu
The experimental measures of the multiplicity derivatives, the moment parameters, the bimodal parameter, the fluctuation of maximum fragment charge number (NVZ), the Fisher exponent ( $τ$ ) and Zipf's law parameter ( $ξ$ ), are examined to search for the liquid-gas phase transition in nuclear multifragmention processes within the framework of the statistical multifragmentation model (SMM). The sensitivities of these measures are studied. All these measures predict a critical signature at or near to the critical point both for the primary and secondary fragments. Among these measures, the total multiplicity derivative and the NVZ provide accurate measures for the critical point from the final cold fragments as well as the primary fragments. The present study will provide a guide for future experiments and analyses in the study of nuclear liquid-gas phase transition.
nucl-thPRC(2018)·16 citations
03
From homogeneous matter to finite nuclei: Role of the effective mass
Hana Gil🇰🇷 · Panagiota Papakonstantinou🇰🇷 · Chang Ho Hyun🇰🇷 · Yongseok Oh🇰🇷
Recent astronomical observations, nuclear-reaction experiments, and microscopic calculations have placed new constraints on the nuclear equation of state (EoS) and revealed that most nuclear structure models fail to satisfy those constraints upon extrapolation to infinite matter. A reverse procedure for imposing EoS constraints on nuclear structure has been elusive. Here we present for the first time a method to generate a microscopic energy density functional (EDF) for nuclei from a given immutable EoS. The method takes advantage of a natural Ansatz for homogeneous nuclear matter, the Kohn-Sham framework, and the Skyrme formalism. We apply it to the realistic nuclear EoS of Akmal-Pandharipande-Ravenhall and describe successfully closed-(sub)shell nuclei. In the process, we provide predictions for the neutron skin thickness of nuclei based directly on the given EoS. Crucially, bulk and static nuclear properties are found practically independent of the assumed effective mass value - a unique result in bridging EDF of finite and homogeneous systems in general.
nucl-thhep-phPRC(2019)·45 citations
04
$Λ^{*} (1405)$ -matter: stable or unstable?
Jaroslava Hrtánková🇨🇿 · Nir Barnea🇮🇱 · Eliahu Friedman🇮🇱 · Avraham Gal🇮🇱 · Jiří Mareš🇨🇿 · Martin Schäfer🇨🇿
A recent suggestion [PLB 774 (2017) 522] that purely- $Λ^{*} (1405)$ nuclei provide the absolute minimum energy in charge-neutral baryon matter for baryon-number $A ≳ 8$ , is tested within RMF calculations. A broad range of $Λ^{*}$ interaction strengths, commensurate with $(K ˉ K ˉ N N)_{I = 0}$ binding energy assumed to be of order 100 MeV, is scanned. It is found that the binding energy per $Λ^{*}$ , $B / A$ , saturates for $A ≳ 120$ with values of $B / A$ considerably below 100 MeV, implying that $Λ^{*} (1405)$ matter is highly unstable against strong decay to $Λ$ and $Σ$ hyperon aggregates. The central density of $Λ^{*}$ matter is found to saturate as well, at roughly twice nuclear matter density. Moreover, it is shown that the underlying very strong $K ˉ N$ potentials, fitted for isospin $I = 0$ to the mass and width values of $Λ^{*} (1405)$ , fail to reproduce values of single-nucleon absorption fractions deduced across the periodic table from $K^{-}$ capture-at-rest bubble chamber experiments.
nucl-thhep-phnucl-exPLB(2018)·15 citations
05
Kinetic freeze out conditions in nuclear collisions with $2 A$ - $158 A$ GeV beam energy within a non-boost-invariant blast-wave model
Sudhir Pandurang Rode🇮🇳 · Partha Pratim Bhaduri🇮🇳 · Amaresh Jaiswal🇮🇳 · Ankhi Roy🇮🇳
We study the kinetic freeze out conditions of bulk hadrons in nuclear collisions. The transverse and longitudinal momentum spectra of the identified hadrons produced in central Au+Au and Pb+Pb collisions, in the beam energy range of $E_{b} = 2 A - 158 A$ GeV are analysed for this purpose, within a generalised non boost-invariant blast wave model. The kinetic freeze out temperature is found to vary in the range of 55 - 90 MeV, whereas the average transverse velocity of collective expansion is found to be around $0.5 c$ to $0.6 c$ . The mean longitudinal velocity of the fireball is seen to increase monotonically with increasing longitudinal boost. The results would be useful to understand the gross collision dynamics for the upcoming experiments at the FAIR and NICA accelerator facilities.
nucl-thhep-phPRC(2018)·17 citations
06
Deuteron production from phase-space coalescence in the UrQMD approach
Sukanya Sombun🇹🇭 · Kristiya Tomuang🇹🇭 · Ayut Limphirat🇹🇭 · Paula Hillmann🇩🇪 · Christoph Herold🇹🇭 · Jan Steinheimer🇩🇪 · Yupeng Yan🇹🇭 · Marcus Bleicher🇩🇪
UrQMD phase-space coalescence calculations for the production of deuterons are compared with available data for various reactions from the GSI/FAIR energy regime up to LHC. It is found that the production process of deuterons, as reflected in their rapidity and transverse momentum distributions in p+p, p+A and A+A collisions at a beam energies starting from the GSI energy regime around 1 AGeV and up to the LHC, are in good agreement with experimental data. We further explore the energy and centrality dependence of the d/p ratios. Finally, we discuss anti-deuteron production for selected systems. Overall, a good description of the experimental data is observed. The results are also compatible with thermal model estimates. Most importantly this good description is based only on a single set of coalescence parameters that is independent of energy system size and can also be applied for anti-deuterons.
nucl-thhep-phnucl-exPRC(2019)·120 citations

Affiliations

first authorsco-authorsvia INSPIRE

Bulk viscosity coefficient of hadronic matter

Sensitivity study of experimental measures for the nuclear liquid-gas phase transition in the statistical multifragmentation model

From homogeneous matter to finite nuclei: Role of the effective mass

Λ∗(1405)-matter: stable or unstable?

Kinetic freeze out conditions in nuclear collisions with 2A - 158A GeV beam energy within a non-boost-invariant blast-wave model

Deuteron production from phase-space coalescence in the UrQMD approach

Affiliations

$Λ^{*} (1405)$ -matter: stable or unstable?

Kinetic freeze out conditions in nuclear collisions with $2 A$ - $158 A$ GeV beam energy within a non-boost-invariant blast-wave model