An experiment has been carried out using the ${}^9\mathrm{Be}({}^3\mathrm{He},t){}^9\mathrm{B}^{*}$ reaction at a beam energy of 33 MeV. A large acceptance silicon-strip array was used to detect the ${}^9\mathrm{B}^{*}$ break-up in coincidence with the triton ejectiles in the high-resolution Munich-Q3D spectrograph. The excitation energy regime $<3$ MeV has been explored and the spectrum resulting from proton decaying states, isolated and characterized. Additional resonance strength is observed at 1.86 MeV $\pm 70$ keV(stat) $\pm 35$ keV(syst), in agreement with two other recent measurements at higher energies and different angles. The consequences for the “missing” ${½}^{+}$ first excited state are discussed. Additionally, the branching ratios for the 2.36 MeV ${5/2}^{-}$ state have been measured as ${\Gamma }_{\alpha 0}/\Gamma =0.98\pm 0.12$ and ${\Gamma }_{p0}/\Gamma =0.016\pm 0.008$, in close agreement with earlier work.

• Received 17 December 2014

DOI:https://doi.org/10.1103/PhysRevC.91.024308