Relativistic Dirac analyses of polarized proton scatterings to the 2(+) gamma vibrational band in Mg-24 and Mg-26

摘要

Relativistic Dirac analyses are performed phenomenologically for the high-lying excited states that belong to the 2(+) gamma vibrational band at the 800 MeV polarized proton inelastic scatterings from the s-d shell nuclei, Mg-24 and Mg-26. Optical potential model is used and scalar and time-like vector potentials are considered as direct potentials. First-order vibrational collective models are used to obtain the transition optical potentials to accommodate the high-lying excited vibrational collective states. The complicated Dirac coupled channel equations are solved phenomenologically to reproduce the differential cross section and analyzing power data by varying the optical potential and deformation parameters. It is found that the relativistic Dirac coupled channel calculation could describe the high-lying excited states of the 2(+) gamma vibrational band at the 800 MeV polarized proton inelastic scatterings from s-d shell nuclei Mg-24 and Mg-26 reasonably well, showing mostly better agreement with the experimental data compared to the results obtained from the nonrelativistic calculations. Calculated deformation parameters for the excited states are analyzed and compared with those of nonrelativistic calculations.