Dirac coupled-channel analyses of the high-lying excited states at Ne-22(p,p')Ne-22

摘要

Dirac phenomenological coupled-channel analyses are performed by using an optical potential model for the high-lying excited vibrational states at 800-MeV unpolarized proton inelastic scatterings from Ne-22 nucleus. Lorentz-covariant scalar and time-like vector potentials are used as direct optical potentials, and the first-order vibrational collective model is used for the transition optical potentials to describe the high-lying excited vibrational collective states. The complicated Dirac coupled-channel equations are solved phenomenologically by using a sequential iteration method by varying the optical potential and the deformation parameters. Relativistic Dirac coupled-channel calculations are able to describe the high-lying excited states of the vibrational bands in Ne-22 clearly better than the nonrelativistic coupled-channel calculations. The channel-coupling effects of the multistep process for the excited states of the vibrational bands are investigated. The deformation parameters obtained from the Dirac phenomenological calculations for the high-lying vibrational excited states in Ne-22 are found to agree well with those obtained from the nonrelativistic calculations using the same Woods-Saxon potential shape.