(p,α) reactions on1p,2s−1dshell nuclei

Abstract

The $^{12}\mathrm{C}(\mathrm{p}, \ensuremath{\alpha})^{9}\mathrm{B}$ and $^{32}\mathrm{S}(\mathrm{p}, \ensuremath{\alpha})^{29}\mathrm{P}$ reactions have been studied at incident energies of 42.77 and 41.9 MeV, respectively. The experimental (p, $\ensuremath{\alpha}$) relative cross sections are well reproduced by distorted wave direct pickup calculations with a semimicroscopic form factor and current shell model wave functions. A comparison between (p, $\ensuremath{\alpha}$) and ($^{3}\mathrm{He}$,d) spectra on $1p$ and $2s\ensuremath{-}1d$ shell nuclei, leading to the same final nucleus, shows a clear evidence of a dominant pickup process over the knockout mechanism in the dynamics of the (p, $\ensuremath{\alpha}$) reaction.NUCLEAR REACTIONS, NUCLEAR STRUCTURE $^{12}\mathrm{C}(\mathrm{p}, \ensuremath{\alpha})^{9}\mathrm{B}$, $E=42.77$ MeV, $^{32}\mathrm{S}(\mathrm{p}, \ensuremath{\alpha})^{29}\mathrm{P}$, $E=41.9$ MeV, measured $\ensuremath{\sigma}({E}_{x}, \ensuremath{\theta})$; natural targets. DWBA analysis. Calculated $^{9}\mathrm{B}$ energy levels, $^{12}\mathrm{C}(\mathrm{p}, \ensuremath{\alpha})^{9}\mathrm{B}$ and $^{32}\mathrm{S}(\mathrm{p}, \ensuremath{\alpha})^{29}\mathrm{P}$ spectroscopic strengths.