Nuclear Theory·nucl-th

Friday·September 6, 2019

10 papers—6 primary·4 cross-listed

01
[Submitted on 5 Sept 2019]
Strangeness production in the new version of the Liège Intra-Nuclear Cascade model
J. Hirtz🇫🇷 · J.-C. David🇫🇷 · A. Boudard🇫🇷 · J. Cugnon🇧🇪 · S. Leray🇫🇷 · I. Leya🇨🇭 · J.L. Rodríguez-Sánchez🇫🇷 · G. Schnabel🇫🇷
The capabilities of the new version of the Liège Intra-Nuclear Cascade model (INCL++6) are presented in detail. This new version INCL is able to handle strange particles, such as kaons and the $Λ$ particle, and the associated reactions and also allows extending nucleon-nucleon collisions up to about $15 - 20$ GeV incident energy. Compared to the previous version, new observables can be studied, e.g., kaon, hyperon, and hypernuclei production cross sections (with the use of a suitable de-excitation code) as well as aspects of kaon-induced spallation reactions. The main purpose of this paper is to present the specific ingredients of the new INCL version and its new features, notably the new variance reduction scheme. We also compare for some illustrative strangeness production cases calculated using this version of INCL with experimental data.
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
1909.02246 [pdf]
PRC(2020)·27 citations
02
[Submitted on 5 Sept 2019]
The key factor to determine the relation between radius and tidal deformability of neutron stars: slope of symmetry energy
Nai-Bo Zhang · Bin Qi · Shou-Yu Wang
The constraints on tidal deformability $Λ$ of neutron stars are first extracted from GW170817 by LIGO and Virgo Collaborations but the relation between radius $R$ and tidal deformability $Λ$ is still nuder debate. Using an isospin-dependent parameterized equation of state (EOS), we study the relation between $R$ and $Λ$ of neutron stars and its dependence on parameters of symmetry energy $E_{sym}$ and EOS of symmetric nuclear matter $E_{0}$ when the mass is fixed as $1.4$ $M_{⊙}$ , $1.0$ $M_{⊙}$ , and $1.8$ $M_{⊙}$ , respectively. We find that, though the changes of high order parameters of $E_{sym}$ and $E_{0}$ can shift the individual values of $R_{1.4}$ and $Λ_{1.4}$ to different values, the $R_{1.4} \sim Λ_{1.4}$ relation approximately locates at the same fitted curve. The slope of symmetry energy $L$ plays the dominated role in determining the $R_{1.4} \sim Λ_{1.4}$ relation. By checking the mass dependence of $R \sim Λ$ relation, the well fitted $R \sim Λ$ relation for 1.4 $M_{⊙}$ is broken for massive neutron stars.
Comments:
7 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Astrophysical Phenomena (astro-ph.HE)
arXiv:
1909.02274 [pdf]
CPC(2020)·8 citations
03
[Submitted on 5 Sept 2019]
Transfer reactions with the Lagrange-mesh method
Shubhchintak · P. Descouvemont
We apply the $R$ -matrix method in Distorted Wave Born Approximation (DWBA) calculations. The internal wave functions are expanded over a Lagrange mesh, which provides an efficient and fast technique to compute matrix elements. We first present an outline of the theory, by emphasizing the $R$ -matrix aspects. The model is applied to the 16O(d,p)7Li and 12C(7Li,t)16O reactions, typical of nucleon and of $α$ transfer, respectively. We illustrate the sensitivity of the cross sections with respect to the $R$ -matrix parameters, and show that an excellent convergence can be achieved with relatively small bases. We also discuss the effects of the remnant term in DWBA calculations, and address the question of the peripherality in transfer reactions. We suggest that uncertainties on spectroscopic factors could be underestimated in the literature.
Comments:
13 pages, 11 figures, accepted for publication at Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1909.02311 [pdf]
PRC(2019)·16 citations
04
[Submitted on 5 Sept 2019]
Microscopic analysis of quasielastic scattering and breakup reactions of neutron-rich nuclei $^{12, 14}$ Be
V.K. Lukyanov · D.N. Kadrev · E.V. Zemlyanaya · K.V. Lukyanov · A.N. Antonov · M.K. Gaidarov
A microscopic analysis of the optical potentials (OPs) and cross sections of quasielastic scattering of $^{12, 14}$ Be on $^{12}$ C at 56 MeV/nucleon and on protons at energy near 700 MeV is carried out. For lower energy scattering the real part of the OP is calculated by using of double-folding procedure accounting for the anti-symmetrization effects, while the imaginary part is obtained on the base of the high-energy approximation (HEA). The HEA is also applied to the calculations of both real and imaginary OPs when solving the relativistic equation for the high-energy proton-nucleus elastic scattering. The neutron and proton density distributions computed in different microscopic models for $^{12}$ Be and $^{14}$ Be are used. In the present hybrid model of the optical potential the only free parameters are the depths of the real and imaginary parts of OP obtained by fitting the experimental data. The role of the inelastic scattering channel to the first excited $2^{+}$ and $3^{-}$ states in $^{12}$ C when calculating the quasielastic cross sections, as well as the modified density of the $^{12}$ C target accounting for the surface effects are studied. In addition, the cluster model, in which $^{14}$ Be consists of a $2 n$ -halo and the $^{12}$ Be core, is applied to calculate the cross sections of diffraction breakup and stripping reactions in $^{14}$ Be+ $^{12}$ C scattering and longitudinal momentum distributions of $^{12}$ Be fragments at energy of 56 MeV/nucleon. A good agreement of the theoretical results with the available experimental data of both quasielstic scattering and breakup processes is obtained.
Comments:
12 pages, 10 figures, 3 tables
Subjects:
Nuclear Theory (nucl-th)
arXiv:
1909.02315 [pdf]
PRC(2019)·3 citations
05
[Submitted on 5 Sept 2019]
Improvement for Color Glass Condensate factorization: single hadron production in pA collisions at next-to-leading order
Hao-Yu Liu🇨🇳 · Yan-Qing Ma🇨🇳 · Kuang-Ta Chao🇨🇳
High order calculation at semi-hard scale is very important, but a satisfactory calculation framework is still missing. We propose a systematic method to regularize rapidity divergences in the CGC factorization, which makes higher order calculation rigorous and straight forward. By applying this method to single hadron production in pA collision, we find the kinematic constraint effect introduced by hand in previous works comes out automatically, but with different values. The difference is crucial for our next-to-leading order (NLO) result to have a smaller theoretical uncertainty comparing with LO result, which makes high order calculation in CGC factorization to be useful. As a byproduct, the negativity problem found in literature can also be overcome in our framework by a proper choosing of factorization scale.
Comments:
10 pages, 3 figures, published version
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
1909.02370 [pdf]
PRD(2019)·27 citations
06
[Submitted on 5 Sept 2019]
A simple family of solutions of relativistic viscous hydrodynamics for fireballs with Hubble flow and ellipsoidal symmetry
M. Csanad🇭🇺 · M. I. Nagy🇭🇺 · Z. F. Jiang🇨🇳 · T. Csorgo🇭🇺
New, analytic solutions of relativistic viscous hydrodynamics are presented, describing expanding fireballs with Hubble-like velocity profile and ellipsoidal symmetry, similar to fireballs created in heavy ion collisions. We find that with these specifications, one obtains solutions where the shear viscosity essentially does not influence the time evolution of the system, thus these solutions are particularly adept tools to study the effect of bulk viscosity alone, which always results in a slower decrease of energy density as well as temperature compared to the case of perfect fluid. We investigate different scenarios for the bulk viscosity and find qualitatively different effects on the time evolution which suggests that there is a possibility to infer the value of bulk viscosity from energy density and temperature measurements in high-energy heavy-ion collisions.
Comments:
9 pages, 4 figures
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Phenomenology (hep-ph)
arXiv:
1909.02498 [pdf]
Gribov-90 Memorial Volume (World Scientif…·6 citations

Affiliations

first authorsco-authorsvia INSPIRE

Strangeness production in the new version of the Liège Intra-Nuclear Cascade model

The key factor to determine the relation between radius and tidal deformability of neutron stars: slope of symmetry energy

Transfer reactions with the Lagrange-mesh method

Microscopic analysis of quasielastic scattering and breakup reactions of neutron-rich nuclei 12,14Be

Improvement for Color Glass Condensate factorization: single hadron production in pA collisions at next-to-leading order

A simple family of solutions of relativistic viscous hydrodynamics for fireballs with Hubble flow and ellipsoidal symmetry

Affiliations

Microscopic analysis of quasielastic scattering and breakup reactions of neutron-rich nuclei $^{12, 14}$ Be