Level Structure ofCa48

Abstract

The elastic and inelastic scattering of 42-MeV alpha particles from ${\mathrm{Ca}}^{48}$ has been studied. The resulting elastic differential cross section has been compared to a parametrized phase-shift analysis, and inelastic angular distributions were generated using an adiabatic method. Comparison with experiment allowed the determination of spins, parities, and transition rates for nine excited states of ${\mathrm{Ca}}^{48}$. The low-lying states (energies in MeV) and their spins and parities are 3.83 ($2^{+}$), 5.15 ($3^{-}$), 6.34 ($1^{-}$), 4.29 ($4^{+}$ or $5^{-}$), 5.37 ($3^{-}$), 6.75 ($2^{+}$), 4.51 ($3^{-}$), 5.73 ($2^{+}$), 7.75 ($3^{-}$). Several other states were excited but cannot be assigned unambiguous quantum numbers. The spectrum of ${\mathrm{Ca}}^{48}$ is compared with that of ${\mathrm{Ca}}^{40}$, and the differences are commented upon.