β-decay spectroscopy on a Tz = - 2 proton-rich nucleus 24Si was performed. The decay scheme of 24Si was reconstructed by the β-delayed γ-ray and proton measurements. Two β branches to the bound 11+ and 12+ states in 24Al were observed for the first time. The observation of the allowed transition firmly established the spin-parity assignment for the 12+ states. The branching ratios to the 11+ and 12+ states were determined to be 31(4)% and 23.9(15)%, respectively. The branching ratios to three unbound states in 24Al including a new level at 6.735MeV were also determined for the first time. The level structure of 24Al was compared with its mirror nucleus 24Na. The Thomas-Ehrman shift on the 12+ state indicates s-wave dominance in the state as well as a characteristic behavior of the weakly bound s-wave proton in 24Al.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics