Addendum to “Measurement of the ${}^8\mathrm{Li}{(\alpha ,n)}^{11}\mathrm{B}$ reaction and astrophysical implications”

In the previous work, we performed direct and exclusive measurements of the ${}^8\mathrm{Li}+\alpha$ reaction and provided cross section data for the ${}^8\mathrm{Li}{(\alpha ,n)}^{11}\mathrm{B}$ reaction [Phys. Rev. C 62, 065801 (2000)]. Recently, we reanalyzed the data and obtained additional cross section data for the ${}^8\mathrm{Li}{(\alpha ,\alpha n)}^7\mathrm{Li}$ reaction at center-of-mass energies between 2.0 and 7.0 MeV; the new data complement those of the ${}^8\mathrm{Li}{(\alpha ,n)}^{11}\mathrm{B}$ reaction obtained in the previous work. The sum of their cross sections is consistent with the reaction cross section of the ${}^8\mathrm{Li}+\alpha$ reaction estimated by a classical formula.

Figure 1

Cross sections obtained in present and previous works [1]. Filled circles and open squares show ${}^8\mathrm{Li}{(\alpha ,\alpha n)}^7\mathrm{Li}$ and ${}^8\mathrm{Li}{(\alpha ,n)}^{11}\mathrm{B}$ reaction cross sections, respectively.

Figure 2

Level schemes of ${}^8\mathrm{Li}+\alpha$ reaction system. Reaction cross sections obtained in previous and present works, intermediate states of compound ${}^{12}\mathrm{B}$, and possible cluster combinations are drawn with energy scale bar. Origin of energy scale is set to the ${}^{12}\mathrm{B}$ excitation energy of 10.01 MeV, which equals the threshold energy of ${}^{12}\mathrm{B}\to \alpha +{}^8\mathrm{Li}$.

Figure 3

Comparison of experimental cross sections with those estimated by classical formula. Diamonds show the sum of present and previous data with error bars and lines to guide the eye. Cross section derived from classical formula is shown by dashed curve. For reference, ${}^8\mathrm{Li}{(\alpha ,n)}^{11}\mathrm{B}$ and ${}^8\mathrm{Li}{(\alpha ,\alpha n)}^7\mathrm{Li}$ cross sections are also plotted without error bars.