The 137La nucleus was populated by the reaction 130Te(11B, 4n) at 40-MeV beam energy and the lifetime
of the 11/2− state at 1004.6 keV was measured using a hybrid array of HPGe clover and LaBr3(Ce) detectors
by electronic fast-timing technique, providing the value T1/2 = 263 ± 12 ps. The reduced transition probability
B(E3) = 23.3 ± 2.4 W.u. is found to be significantly larger compared to the values observed in lighter odd-A La
isotopes. The experimentally determined B(E3) value is compared with theoretical calculations of random-phase
approximation which explains the enhanced transition probability to be arising from higher contribution of the
g9/2 orbital to the proton transition density.
