Multiparticle M1 band in La-134

Abstract

Lifetimes of seven low-lying excited states of La-134 in the picosecond range have been determined by the recoil distance method (RDM). Lifetimes of six states, belonging to a strong M1 band and having shorter lifetimes, have been determined by the Doppler shift attenuation method (DSAM). This band with intense M1 transitions and very few weak E2 crossovers appeared to be due to magnetic rotation. However, such a possibility is ruled out because roughly constant values of B(M1) were found from the lifetime results. The semiclassical model was utilized to calculate the B(M1) values; and after being compared with the experimental results, the band was assigned the multiparticle configuration pi g(7/2)circle times nu h(11/2)(h(11/2))(2), which differs from the earlier assignment of pi h(11/2)circle times nu g(7/2)(h(11/2))(2).