The low-energy ${}^6\mathrm{H}\mathrm{e}+p,$ ${}^6\mathrm{H}\mathrm{e}\left({p,n)}^6\mathrm{Li}{(1\mathrm{}}^{+}{,0\mathrm{}}^{+}\right),$ and ${}^6\mathrm{H}\mathrm{e}(p,\alpha )t$ reactions are studied in the framework of a microscopic multicluster model. The ${}^6\mathrm{He},$ ${}^6\mathrm{Li},$ and t wave functions are calculated variationally with microscopic three-cluster structures. The different thresholds are fairly well reproduced. The model provides the experimentally known states and resonances of ${}^7\mathrm{Li}$ up to $E_x=12\mathrm{}\hspace{0.5em}\mathrm{MeV}$ except the second ${7/2}^{-}$ state. A ${3/2}^{-};T=3/2\mathrm{}$ resonance is obtained which should correspond to the experimental ${3/2}^{-};3/2\mathrm{}$ resonance at $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=1.27\mathrm{}\hspace{0.5em}\mathrm{}\mathrm{MeV}.$ This resonance might have a halo structure. The ${}^6\mathrm{H}\mathrm{e}({p,n)}^6\mathrm{Li}{(0\mathrm{}}^{+};$ 3.56 MeV) cross section should be strongly affected by this resonance. Cross sections are also calculated for the ${}^6\mathrm{H}\mathrm{e}+p$ elastic scattering and for the ${}^6\mathrm{H}\mathrm{e}(p,\alpha )t$ transfer reaction. The ${}^6\mathrm{H}\mathrm{e}+n$ elastic phase shifts are determined with a similar model and provide the isobaric analog ${3/2}^{-}$ ground state of ${}^7\mathrm{He}$ and a ${1/2}^{-}$ excited state.

• Received 9 November 2000

DOI:https://doi.org/10.1103/PhysRevC.63.044611