Proton-induced reactions on6Heat low energies

Finite-range coupled channel calculations of proton-induced reactions on ${}^6\mathrm{He}$ have been performed below the ${}^6\mathrm{He}$ three-body breakup threshold, assuming that the $\alpha$ particle core is inert. The coupling scheme included all transitions between open channels and therefore no imaginary parts of the interaction potentials were used. The calculations have revealed a complicated dynamics of the ${p+}^6\mathrm{He}$ interaction at the chosen energy, with couplings to all open channels being important to generate the final cross sections. The total absorption from the elastic ${p+}^6\mathrm{He}$ channel depends on the details of the interactions employed in the three-body model of ${}^6\mathrm{He}$ and shows a strong correlation with the r.m.s. radius of ${}^6\mathrm{He}.$ The role of the exchange mechanisms was investigated within the framework of the distorted-wave Born approximation. It was found that both the triton exchange ${}^6\mathrm{He}{(p,}^4\mathrm{He})t$ and two-neutron ${}^6\mathrm{He}{\mathrm{}(p,t)\mathrm{}}^4\mathrm{He}$ direct transfer mechanisms produce comparable cross sections. The investigation of the radiative capture ${}^6\mathrm{He}(p,\gamma {)}^7\mathrm{Li}$ in the potential model shows strong suppression of the $E1\mathrm{}$ transition because of the destructive interference between the external and internal contributions to the reaction amplitude and the absorption in the incident channel.