Based on the Boltzmann-Uehling-Uhlenbeck equation, we investigate the effects of the isovector nucleon effective mass $m_{v,0}^{*}$ and the in-medium nucleon-nucleon cross section ${\sigma }^{*}$ on the isovector giant dipole resonance (IVGDR) in ${}^{208}\mathrm{Pb}$, employing a set of representative Skyrme energy density functionals. We find that the energy-weighted sum rule $m_1$ of the IVGDR is highly sensitive to $m_{v,0}^{*}$ and only mildly dependent on ${\sigma }^{*}$, while the width $\mathrm{\Gamma }$ of the IVGDR is primarily governed by ${\sigma }^{*}$ with a moderate sensitivity to $m_{v,0}^{*}$. From a Bayesian analysis of both $m_1$ and $\mathrm{\Gamma }$, we infer that the $m_{v,0}^{*}/m$ = $0.{730}_{-0.034}^{+0.036}$, where $m$ is the bare nucleon mass. Furthermore, by incorporating the isoscalar nucleon effective mass $m_{s,0}^{*}/m=0.820\pm 0.030$, extracted from the isoscalar giant quadrupole resonance in ${}^{208}\mathrm{Pb}$, the linear neutron-proton effective mass splitting coefficient at saturation density ${\rho }_0$ is determined to be $\mathrm{\Delta }{m}_1^{*}\left({\rho }_0\right)/m=0.{202}_{-0.114}^{+0.118}$.

Close

PrevNext

View figure in article

• Giant resonances
• Models & methods for nuclear reactions
• Nuclear matter
• Nuclear reactions
• 190 ≤ A ≤ 219