Observation and empirical shell-model study of new yrast excited states in the nucleus Ce-142

Excited states of Ce-142, populated in deep inelastic reactions of Se-82 projectiles bombarding La-139 target, have been studied to medium spins using in-beam gamma spectroscopy techniques. Three new levels have been identified at 2625, 2995 and 3834keV, and assigned as 8(+), 9((-)) and 11((-)) respectively, based on the analysis of the properties of gamma transitions. These new yrast states follow well the level systematics of N = 84 isotones. Their structures have been discussed with the help of empirical shell-model calculations.