Dirac Coupled-channel Analyses of Polarized Proton Scatterings to the 2$^+$ Gamma Vibrational Band in $^{24}$Mg and $^{26}$Mg

TL;DR

This study uses relativistic Dirac coupled channel calculations to analyze high-lying 2+ gamma vibrational states in $^{24}$Mg and $^{26}$Mg via 800-MeV polarized proton inelastic scattering, showing improved agreement over nonrelativistic methods.

Contribution

It introduces a relativistic Dirac coupled channel approach to better describe high-lying vibrational states in light nuclei during proton scattering.

Findings

Relativistic calculations fit experimental data better than nonrelativistic ones.

Deformation parameters for excited states are obtained and compared.

The method successfully reproduces differential cross sections and analyzing powers.

Abstract

Dirac coupled channel calculations 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, $^{24}$Mg and $^{26}$Mg. 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 in order 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 $^{24}$Mg and $^{26}$Mg reasonably well, showing 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.