Nature of 10 MeV state in ¹²C

Abstract

We performed a coincidence measurement of decay-α particles by using inelastic scattering of 386 MeV α particles on 12C. We obtained further evidence for the second 2+ state at 9.84 MeV, which we found in previous work, from angular correlation functions for decay-α particles. The coincidence energy spectra with the α-decay to the ground state and the first excited 2+ state in 8Be from the 10 MeV states in 12C were obtained. They indicated the broad 0+ state at 10 MeV consists of two components. The lower 0+ state do α decay to the ground state of 8Be only. The higher 0+ state has a distinct peak at 10.8 MeV with a width of 0.4 MeV in the coincidence spectrum for the first excited state of 8Be channel. They have consistent properties predicted for a higher nodal state of the Hoyle state and a linear-like 3α state, respectively.