The $\alpha {+}^6\mathrm{He}$ elastic scattering is investigated within a microscopic multicluster model, involving a realistic description of the ${}^6\mathrm{He}$ halo nucleus. Phase shifts and elastic-scattering cross sections are calculated up to $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=15\mathrm{}\hspace{0.5em}\mathrm{MeV}$ with two variants of the resonating-group method. The model gives rise to $1^{-}$ and $3^{-}$ molecular states near $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=0.5\mathrm{}\hspace{0.5em}\mathrm{MeV}$ and $E_{\mathrm{c}.\mathrm{m}.\mathrm{}}=3.7\mathrm{}\hspace{0.5em}\mathrm{MeV},$ respectively. We suggest that the broad $3^{-}$ resonance should be observable by comparing elastic cross sections at different energies. We also evaluate the order of magnitude of the ${}^6\mathrm{He}$ breakup cross section.

• Received 17 August 1998

DOI:https://doi.org/10.1103/PhysRevC.59.817