High-spin structures of 124−131Te: Competition of proton- and neutron-pair breakings

The 124−131Te nuclei have been produced as fission fragments in two fusion reactions inducedby heavy ions (12C+238U at 90MeV bombarding energy and 18O+208Pb at 85MeV) and studied withthe Euroball array. Their high-spin level schemes have been extended up to 6MeV (even-A) and 5MeV(odd-A) excitation energies from the triple γ-ray coincidence data. The γ-γ angular correlations have beenanalyzed in order to assign spin and parity values to most of the observed states. Moreover the half-livesof isomeric states have been measured from the delayed coincidences between the fission-fragment detectorSAPhIR and Euroball, as well as from the timing information of the Ge detectors. The behaviors of theyrast structures identified in the present work are first discussed in comparison with the general featuresknown in the mass region, particularly the breakings of neutron pairs occupying the νh11/2 orbit identifiedin the neighboring Sn nuclei. The experimental level schemes are then compared to shell-model calculationsperformed in this work. The analysis of the wave functions shows the effects of the proton-pair breakingalong the yrast lines of the heavy Te isotopes