Two-proton decay of the isobaric analogue state of Ar-31

Abstract

We have studied several two proton branches in the β-decay of Ar-31, the most intensive ones proceeding through the isobaric analogue state (IAS) in Cl-31. The energy and angular correlations of the two protons originating from the IAS have been measured. An indication of non-isotropic emission has been observed in the p+p+P-29 branch. The energy spectra of protons from the IAS 2p-branches seem to be continuous, which is difficult to explain by a sequential emission through a few intermediate levels in S-30. The model of non-sequential or democratic three-particle decay gives the best fit to the present data favoring the IAS spin-parity 5/2(+).