Neutron skin thickness of 90Zr and symmetry energy constrained by charge exchange spin-dipole excitations

The charge exchange spin-dipole (SD) excitations of Zr-90 are studied using the Skyrme Hartee-Fock plus proton-neutron random phase approximation with SAMi-J interactions. The experimental value of the model-independent sum rule obtained from the SD strength distributions of Zr-90(p, n)Nb-90 and Zr-90(n,p)Y-90 is used to deduce the neutron skin thickness. The neutron skin thickness ?r(np) of Zr-90 is extracted as 90 0.083 +/- 0.032 fm, which is similar to the results of other studies. Based on the correlation analysis of the neutron skin thickness and the ?r(np) nuclear symmetry energy J as well as its slope parameter L, a constraint from the extracted ?r(np) leads to the limitation of J to 29.2 +/- 2.6 MeV and L to 53.3 +/- 28.2 MeV.

Automated summary

The study investigates the charge exchange spin-dipole (SD) excitations of Zr-90 using the Skyrme Hartee-Fock plus proton-neutron random phase approximation with SAMi-J interactions. The experimental value of the model-independent sum rule obtained from the SD strength distributions of Zr-90(p, n)Nb-90 and Zr-90(n,p)Y-90 is used to determine the neutron skin thickness. The extracted neutron skin thickness ?r(np) of Zr-90 is 90 0.083 +/- 0.032 fm, which is consistent with previous studies. Based on correlation analysis, the extracted ?r(np) imposes constraints on the nuclear symmetry energy J (29.2 +/- 2.6 MeV) and its slope parameter L (53.3 +/- 28.2 MeV).