Bayesian inference on isospin splitting of nucleon effective mass from giant resonances in 208Pb *

Abstract

Abstract From a Bayesian analysis of the electric dipole polarizability, the constrained energy of isovector giant dipole resonance, the peak energy of isocalar giant quadrupole resonance, and the constrained energy of isocalar giant monopole resonance in 208Pb, we extract the isoscalar and isovector effective masses in nuclear matter at saturation density as and , respectively, at 90% confidence level. The constraints obtained on and lead to a positive isospin splitting of nucleon effective mass in asymmetric nuclear matter of isospin asymmetry at as . In addition, the symmetry energy at the subsaturation density is determined to be MeV at 90% confidence level.