Elastic and inelastic scattering of 0.8 GeV polarized protons from 24Mg and 26Mg.

Abstract

Data on 800 MeV polarized proton scattering on $^{24}\mathrm{Mg}$ and $^{26}\mathrm{Mg}$ are presented. Angular distributions and analyzing power data have been extracted from fits to 26 peaks in the spectra for $^{24}\mathrm{Mg}$ and 23 peaks in $^{26}\mathrm{Mg}$. Although there are a variety of shapes for the angular distributions, the analyzing power data for all states are positive and similar in magnitude and seem to be consistent with a two-body operator for the excitation with a spin structure much like that for the free proton-nucleon system. Evidence for a level in $^{26}\mathrm{Mg}$ at 8.03 MeV with J>4 is presented. Comparison between the observed angular distribution, coupled channels, and distorted wave Born approximation calculations, and the angular distributions of excited states in neighboring nuclei, support the assignment of ${J}^{\ensuremath{\pi}}$${=5}^{\mathrm{\ensuremath{-}}}$ or ${6}^{+}$. Coupled channels calculations for the ${0}^{+}$, ${2}^{+}$, ${4}^{+}$,${\phantom{\rule{0ex}{0ex}}\mathrm{and}\phantom{\rule{0ex}{0ex}}6}^{+}$ members of the ground state rotational bands of $^{24}\mathrm{Mg}$ and $^{26}\mathrm{Mg}$ are compared to the data. Deformation parameters from distorted wave Born approximation calculations are determined for most of the angular distributions.