Proton scattering by short lived sulfur isotopes

Abstract

Elastic and inelastic proton scattering has been measured in inverse kinematics on the unstable nucleus ${}^{40}\mathrm{S}$. A phenomenological distorted wave Born approximation analysis yields a quadrupole deformation parameter ${\ensuremath{\beta}}_{2}=0.35\ifmmode\pm\else\textpm\fi{}0.05$ for the ${2}_{1}^{+}$ state. Consistent phenomenological and microscopic proton scattering analyses have been applied to all even-even sulfur isotopes from $A=32$ to $A=40$. The second analysis used microscopic collective model densities and a modified Jeukenne-Lejeune-Mahaux nucleon-nucleon effective interaction. This microscopic analysis suggests the presence of a neutron skin in the heavy sulfur isotopes. The analysis is consistent with normalization values for ${\ensuremath{\lambda}}_{v}$ and ${\ensuremath{\lambda}}_{w}$ of 0.95 for both the real and imaginary parts of the Jeukenne-Lejeune-Mahaux potential.