Free spectator nucleons in ultracentral relativistic heavy-ion collisions as a probe of neutron skin

Lu-Meng Liu, Chun-Jian Zhang, Jun Xu +2

Besides the yield ratio of free spectator neutrons produced in ultracentral ${}^{96}$Zr+${}^{96}$Zr to ${}^{96}$Ru+${}^{96}$Ru collisions, we propose that the yield ratio $N_n/N_p$ of free…