Proton and neutron contributions to the first 2⁺ state of ⁴²Si via inelastic scattering

The N=28 nucleus ⁴²Si has been studied via Coulomb excitation and inverse-kinematics proton scattering with the Gretina gamma-ray tracking array and the S800 Magnetic Spectrograph at the Facility for Rare Isotope Beams at Michigan State University. The ratio M_n/M_p of relative contributions of neutrons and protons to the first 2⁺ state has been determined from the measured B(E2) value and proton-scattering deformation length. This result will be discussed in the context of systematic evolution of the N=28 shell below ⁴⁸Ca.