Abstract
The high-spin structures of the N = 81 isotones 135Xe and 137Ba are investigated after multinucleontransfer (MNT) and fusion-evaporation reactions. Both nuclei are populated in (i) 136Xe+238U and (ii) 136Xe+208Pb MNT reactions employing the high-resolution Advanced Gamma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (iii), in the 136Xe+198Pt MNT reaction employing the -ray array GAMMASPHERE in combination with the gas detector array Chico, and (iv) via a 11B+130Te fusion-evaporation reaction. The high-spin level schemes of 135Xe and 137Ba are considerably extended to higher energies. The 2058-keV (19=2 ) state in 135Xe is identified as an isomer, completing the systematics for the N = 81 isotones. Its half-life is measured to be 8.6(10) ns, corresponding to a transition probability of B(E2; 19=2 ! 15=2 ) = 0:539(69) W.u. Latest shell model calculations considering 132Sn as a closed core reproduce the experimental findings and provide guidance to the interpretation of the new levels. The experimentally deduced reduced quadrupole transition probabilities of the isomeric states are compared to shell-model predictions.