Rotational states in26Mg

Abstract

The decay properties of the levels at 3.941(3+), 5.476(4+) and 5.716 MeV (4+) in 26Mg have been investigated. Particle gamma-ray angular correlations were measured following the reactions 26Mg( alpha , alpha ' gamma )26Mg and 26Mg(p,p' gamma )26Mg enabling accurate branching ratios and E2/M1 mixing ratios to be determined. The lifetimes were obtained with the reaction 23Na( alpha ,p gamma )26Mg using the Doppler shift attenuation method. The transition from the 5.476(4+) to the 3.941 MeV (3+) state is shown to have an E2 strength of 12+9-4 Weisskopf units whilst the transitions from the 3.941 MeV state itself are essentially dipole. The data together with the revised branching ratios result in a new assignment of states to the Kpi =2+ and 3+ rotational bands.