Systematics of (α,C12) in light nuclei and implications for multi-α-cluster transfer reactions

Abstract

The $^{16}\mathrm{O}$, $^{24,26}\mathrm{Mg}$, $^{28}\mathrm{Si}$, $^{32}\mathrm{S}$, $^{40}\mathrm{Ca}$($\ensuremath{\alpha},^{12}\mathrm{C}$) reactions have been studied at ${E}_{\ensuremath{\alpha}}=90.3$ MeV. The observed cross sections fall off rapidly with increasing target mass $A_{t}^{}{}_{}{}^{\ensuremath{-}5\ifmmode\pm\else\textpm\fi{}1}$, consistent with predictions for direct $^{8}\mathrm{Be}$ or successive $\ensuremath{\alpha}$ transfer employing first-order S${\mathrm{U}}_{3}$ cluster overlap amplitudes, although other, more complicated mecanisms cannot be excluded. The results are extrapolated and estimates of multi-$\ensuremath{\alpha}$-cluster transfer cross sections in heavy nuclei, such as those proposed to synthesize superheavy elements, are obtained.NUCLEAR REACTIONS $^{16}\mathrm{O}$, $^{24,26}\mathrm{Mg}$, $^{28}\mathrm{Si}$, $^{40}\mathrm{Ca}$($\ensuremath{\alpha},^{12}\mathrm{C}$); measured $\ensuremath{\sigma}({E}_{^{12}\mathrm{C}},15\ifmmode^\circ\else\textdegree\fi{})$; inferred target-mass dependence; extrapolated multi-$\ensuremath{\alpha}$-cluster transfer cross sections for heavy nuclei relevant for synthesis of superheavy elements.