Proton scattering on the unstable {sup 38}S nucleus: Isovector contribution to the 2{sub 1}{sup +} state

A 39A MeV {sup 38}S radioactive beam was used with inverse kinematicsto measure angular distributions for elastic and inelastic proton scattering from a CH{sub 2} target. Optical potential and folding model calculations are compared with the elastic distribution. Using coupled channel calculations, the {beta}{sub 2} value for the 2{sub 1}{sup +} state is determined to be 0.35{plus_minus}0.04. This value, when compared with the corresponding result from a Coulomb excitationmeasurement, leads to M{sub n}/M{sub p}=(1.5{plus_minus}0.3) N/Z, indicating an isovectorcontribution to the 2{sub 1}{sup +} state of {sup 38}S. {copyright} {ital 1997} {ital The American Physical Society}