Dependence of neutron-proton matrix element ratios of 2 1 + states in58,60,62,64Ni on ground state neutron-proton density distribution differences

We investigate the dependence of the neutron-proton matrix element ratios (η) on radial neutron and proton ground state density distribution differences (Δ ^np) within the framework of the shell model quasiparticle random phase approximation. We show that theη ratios are linearly dependent onΔ _rms ^np differences. We prove the consistency of empirical and theoretical methods by agreement of theη ratios obtained from the 1 GeV proton inelastic scattering analysis and from the QRPA calculations.