Anomalous populations of particle-unbound states in ¹⁰B

Relative populations of particle unstable states in ¹⁰B were measured for the normal kinematics reactions ¹⁴N+²⁷Al and ¹⁴N+¹⁹⁷Au at E/A=75 MeV, the nearly symmetric reaction ¹²⁹Xe+¹²²Sn at E/A=31 MeV, and the inverse kinematics reaction ¹²⁹Xe+²⁷Al at E/A=31 MeV. In all cases, populations of excited states are incompatible with statistical populations of the known excited states of this nucleus. For the ¹²⁹induced reactions, discrepancies are smaller than for the ¹⁴induced reactions. The overall agreement with statistical calculations is improved by assuming a proposed but not confirmed 3⁺ excited state contributing to the group of levels at E^*=6 MeV.