Gamma-ray fast-timing coincidence measurements from the super(18)O+ super(18)O fusion-evaporation reaction using a mixed LaBr sub(3)-HPGe array

We report on a gamma-ray coincidence analysis using a mixed array of hyperpure germanium and cerium-doped lanthanum tri-bromide (LaBr sub(3):Ce) scintillation detectors to study nuclear electromagnetic transition rates in the pico-to-nanosecond time regime in super(33,34)P and super(33)S following fusionaevaporation reactions between an super(18)O beam and an isotopically enriched super(18)O implanted tantalum target. Energies from decay gamma-rays associated with the reaction residues were measured in event-by-event coincidence mode, with the measured time difference information between the pairs of gamma-rays in each event also recorded using the ultra-fast coincidence timing technique. The experiment used the good full-energy peak resolution of the LaBr sub(3): Ce detectors coupled with their excellent timing responses in order to determine the excited state lifetime associated with the lowest lying, cross-shell, I super( pi ) = 4- "intruder" state previously reported in the N=19 isotone super(34)P. The extracted lifetime is consistent with a mainly single-particle M2 multipolarity associated with a f sub(7/2) arrow right d sub(5/2) single particle transition.