Nucleon-Δ elastic cross section in isospin-asymmetric nuclear medium with inclusion of scalar-isovector <i>δ</i> meson field*

Abstract The production, dynamic evolution, and decay of particles play a crucial role in understanding the properties of high baryon density nuclear matter in intermediate-energy heavy-ion collisions. In this study, energy-, density-, and isospin-dependent nucleon- elastic cross sections ( ) were studied within the framework of the relativistic Boltzmann-Uehling-Uhlenbeck transport theory, in which the meson field is considered in addition to the , , and meson fields. The results show that the and meson related exchange terms have a nonnegligible contribution to compared to only considering the meson exchange terms, although there is a significant cancellation of the cross section among these meson exchange terms. In addition, owing to the different effects of the medium correction on the effective masses of neutrons, protons, and differently charged s, the individual exhibits an ordered isospin-asymmetry ( ) dependence, and and have opposite dependencies. Moreover, the dependence of the ratio for reaction channels satisfies , while for , it satisfies . In addition, the results indicate that the isospin effect on , which is mostly caused by the isovector and meson fields, is still significant at densities up to three times the normal nuclear density. Finally, a parametrization of the energy-, density-, and isospin-dependent elastic cross sections is proposed based on the microscopic calculated results. Thus, the in-medium in the energy range of =2.3~3.0 GeV can be properly described.