Evidence for a 3.8 MeV state in Be 9

The breakup reaction $^{9}\mathrm{Be}(^{4}\mathrm{He},3\ensuremath{\alpha})\mathit{n}$ was measured using an array of four double-sided silicon strip detectors at beam energies of 22 and 26 MeV. Excited states in $^{9}\mathrm{Be}$ up to 8 MeV were populated and reconstructed through measurements of the charged reaction products. Evidence is given for a state in $^{9}\mathrm{Be}$ at $3.{82}_{\text{-0.09}}^{\text{+0.08}}$ MeV with $\mathrm{\ensuremath{\Gamma}}={1240}_{\text{-90}}^{\text{+270}}$ keV. This is consistent with two recent measurements of a state with similar properties in the mirror nucleus $^{9}\mathrm{B}$. An analysis of the reduced widths ($^{8}\mathrm{Be}_{\mathrm{g}.\mathrm{s}.}$ channel) of this state along with the proposed mirror state has led to a firm limit of $J\ensuremath{\le}7/2$ and a tentative assignment of ${J}^{\ensuremath{\pi}}=1/{2}^{\ensuremath{-}}$ or $3/{2}^{\ensuremath{-}}$.