Reaction rates with temperature-dependent cross sections: A quantum dynamical microscopic model for the neutron capture reaction on the $^{188}$Os target (2509.12404v1)

Abstract: The neutron capture process plays a vital role in creating the heavy elements in the universe. The environments involved in these processes are, in general, high in temperature and are characterized by two distinct reaction mechanisms: the slow and rapid neutron capture processes. In this work, the slow neutron capture process is described with the time-dependent coupled channels wave-packet (TDCCWP) method that uses both a many-body nuclear potential and an initial temperature-dependent state to account for the thermal environment. To evaluate the role of a mixed and entangled initial state in the temperature-dependent neutron capture cross section, TDCCWP calculations are compared with those from the coupled-channels density matrix (CCDM) method based on the Lindblad equation. The importance of the temperature of the environment is then explored in the n+$^{188}$Os reaction with a decrease of cross section with increasing temperature, along with a decrease of $10\%$ in reaction rates for the highest incident energies studied, which are important in the rapid neutron capture process.