Evidence for a new C12 state at 13.3 MeV

Abstract

The two reactions C12(He4,He4+He4+He4)He4 and Be9(He4, He4+He4+He4)n were measured using an array of four double-sided strip detectors. Excited states in C12 were reconstructed filtered by the condition that the α-decay proceeded via the Be8 ground state. In both measurements, evidence was found for a new state at 13.3(0.2) MeV with a width 1.7(0.2) MeV. Angular correlation measurements from the C12(He4, He4+He4+He4)He4 reaction indicates that the state may have Jπ=4+. © 2011 American Physical Society.