Triton-He3relative and differential flows as probes of the nuclear symmetry energy at supra-saturation densities

Abstract

Using a transport model coupled with a phase-space coalescence afterburner, we study the triton-3 He (t-3 He) ratio with both relative and differential transverse flows in semicentral 132 Sn + 124 Sn reactions at a beam energy of 400 MeV/nucleon. The neutron-proton ratios with relative and differential flows are also discussed as a reference. We find that similar to the neutron-proton pairs, the t-3 He pairs also carry interesting information regarding the density dependence of the nuclear symmetry energy. Moreover, the nuclear symmetry energy affects more strongly the t-3 He relative and differential flows than the π − /π + ratio in the same reaction. The t-3 He relative flow can be used as a particularly powerful probe of the high-density behavior of the nuclear symmetry energy.

Nuclear symmetry energy: An experimental overview

“…Preliminary calculation by Yong et al [46], suggests that a "stiff" (x = 0) dependence of the symmetry energy would lead to a linear behavior for the relative flow, whereas the"soft" (x = 1) dependence would give a non linear behavior with appreciable difference between the two. So it is expected that a measurement of this observable should provide important information on the high density behavior of the symmetry energy.…”

“…Another observable that has been suggested for probing the high density behavior of the symmetry energy is the relative and differential collective flow between triton and 3 He particles [46]. Preliminary calculation by Yong et al [46], suggests that a "stiff" (x = 0) dependence of the symmetry energy would lead to a linear behavior for the relative flow, whereas the"soft" (x = 1) dependence would give a non linear behavior with appreciable difference between the two.…”

Model dependence of isospin sensitive observables at high densities

“…The BUU transport model is usually used to describe one-body observable although some afterburner can be added to predict many-body correlation [27]. The other frequently utilized approaches is the Molecular Dynamics Model (QMD), which represents the individual nucleons as Gaussian "wave-packet" with mean values that move according to the Hamilton's equations [28].…”

Spin transport in intermediate-energy heavy-ion collisions as a probe of in-medium spin–orbit interactions

“…[40] and references therein). These hybrid models have been shown to be effective and reasonable in describing observables of light clusters, such as their multiplicities [41][42][43][44][45] and collective flows [46][47][48][49][50]. In the present study, we adopt a dynamical coalescence model which evaluates the probability of producing a cluster by the overlap of its Wigner phase-space density with daughter nucleons [45,47].…”