Properties of the 12C 10 MeV state determined through β-decay

The β-delayed triple-α particle decay of 12B has been measured with a setup that favours coincidence detection. A broad state in 12C, previously reported around 10 MeV, has been seen and its properties determined through R-matrix analysis of the excitation spectrum. The spin and parity are 0+. Interference between this state and the Hoyle state at 7.654 MeV has a marked influence on the spectrum. The coupling between the two states makes it difficult to determine the resonance energy.