Shear viscosity from nuclear stopping

Abstract

Within a Boltzmann transport model, we demonstrate correlation between stopping observables and shear viscosity in central nuclear collisions at intermediate energies (on the order of 10-1000MeV/nucleon). The correlation allows us to assess the viscosity of nuclear matter, by tuning the in-medium nucleon-nucleon cross section in our transport model to agree with nuclear stopping data. We also calculate the ratio of shear viscosity to entropy density to determine how close the system is to the universal quantum lower limit proposed in the context of ultrarelativistic heavy ion collisions. * bbarker@roosevelt.edu 1 arXiv:1612.04874v3 [nucl-th]

Revisiting an extended-mean-field approach in heavy-ion collisions around the Fermi energy

“…It has been demonstrated in all previous investigations [18][19][20][21][22][23][24][25]28] that, to agree with experimental results on stopping, the cross section responsible for the two-body dissipation in Eq. ( 19) should be strongly reduced relative to the free-space N N cross section σ free NN in order to account for its in-medium modification.…”

“…Several experimental observations are sensitive to the nuclear stopping power [16,17,26,27]. These observables have recently been abundantly investigated by a number of model-studies of HIC (IQMD [18][19][20][21], AMD [22], SMF [23], UrQMD [24], LV [25], and BUU [28]) in order to constrain the elastic N N cross section inherent to these models. In Fig.…”

Constraining the in-medium nucleon-nucleon cross section from the width of nuclear giant dipole resonance

“…The in-medium nucleon-nucleon (NN) cross section σ * NN has significant effects on the dynamics of heavy-ion collisions (HICs), and it thus plays a crucial role in understanding the reaction mechanisms as well as various phenomena and observables in these collisions [1][2][3][4][5][6]. The importance of σ * NN also lies in its intimate relation to the transport properties of nuclear matter [7,8] and the nucleon effective interactions [9]. Since a major goal of studying HICs is to extract the equation of state (EOS) of nuclear matter from experimental data [10][11][12][13][14][15], a thorough understanding of σ * NN helps reduce the uncertainties in transport models [16,17] that are used for describing these reactions.…”

“…Email addresses: wangrui@sinap.ac.cn (Rui Wang), zhangzh275@mail.sysu.edu.cn (Zhen Zhang), lwchen@sjtu.edu.cn (Lie-Wen Chen), ko@comp.tamu.edu (Che Ming Ko), mayugang@fudan.edu.cn (Yu-Gang Ma) in HICs that are sensitive to σ * NN , e.g., the collective flow and nuclear stopping [1,8,[26][27][28][29][30]. Although these studies have reached the consensus that the NN cross section is suppressed in nuclear medium, the reduction factor is still far from certainty.…”

Nuclear Collective Dynamics in Transport Model With the Lattice Hamiltonian Method

“…As shown in reference [55], in order to reproduce the experimental GDR width of 208 Pb obtained at the RCNP, a strong medium reduction of the NN cross-section is needed. There are many parameterizations for the medium reduction of the NN cross-section [104][105][106][107], which could be dependent on density, collision energy, or isospin. As an example, we choose the FU4FP6 parameterization [107] for the medium reduction of the cross-section to calculate the strength function and width of the GDR in 208 Pb.…”