Unexpected spin-parity assignments of the excited states inBe9

The excited states in the light nucleus $^{9}\mathrm{Be}$ are studied through $\ensuremath{\beta}$-delayed neutron decays from spin-polarized ${}^{9}{\mathrm{Li}}_{\mathrm{g}.\mathrm{s}.}$. The neutron transitions via ${}^{5}{\mathrm{He}}_{\mathrm{g}.\mathrm{s}.}$ from the 2.43-, 2.78-, 4.704-, 5.59-, and 7.94-MeV states in $^{9}\mathrm{Be}$ are observed for the first time, and the spins and parities (${I}^{\ensuremath{\pi}}$'s) of the excited states in $^{9}\mathrm{Be}$ are assigned from $\ensuremath{\beta}\text{\ensuremath{-}}n$ coincidences and measurements of the $\ensuremath{\beta}$-decay asymmetries. The spin parity, ${I}^{\ensuremath{\pi}}$, of the 2.43-MeV state is assigned to be $5/{2}^{\ensuremath{-}}$, which is consistent with the reported value. The present results suggest that the ${I}^{\ensuremath{\pi}}$ values of the 2.78-, 4.704-, 5.59-, and 7.94-MeV states are $3/{2}^{\ensuremath{-}}$, $1/{2}^{\ensuremath{-}}$, $5/{2}^{\ensuremath{-}}$, and $3/{2}^{\ensuremath{-}}$, respectively, which are different from early reported values. However, shell-model calculations of the $p$ shell are in overall good agreement with the present results, except for the ${I}^{\ensuremath{\pi}}$ values of the 2.78- and 4.704-MeV states.