Importance of $\alpha$-induced reactions and the inverse $(\gamma,\alpha)$ on $p$-nuclei

Abstract

We have calculated astrophysical reaction cross-sections for $(\gamma,\alpha)$ reactions of some nuclei important for the calculation of $p$-process reaction-decay network. Reaction rates for $\alpha$-induced reactions are calculated with the semi-microscopic optical potential constructed using double folding method, where nuclear density distributions for finite nuclei along with the effective nucleon-nucleon interaction are the important components of the folded potential. For this purpose density distributions of target nuclei are obtained from relativistic mean field approach. Astrophysical reaction cross section for elastic scattering of $\alpha$-particle from $^{92}$Mo target is compared with the existing experimental results to constrain the newly formed potential. Further, to check the credibility of the present theoretical framework, the astrophysical S-factor for ($\alpha$,$\gamma$) reactions are compared with the experimental observation, wherever available. Finally, an estimate of dominant photodisintegration channels at various astrophysical temperature is discussed for $p$-nuclei $^{74}$Se and $^{96}$Ru.