The mutable nature of particle-core excitations with spin in the one-valence-proton nucleus 133Sb

Autor: Bocchi, G., Leoni, S., Fornal, B., Colo', G., Bortignon, P. F., Bottoni, S., Bracco, A., Michelagnoli, C., Bazzacco, D., Blanc, A., De France, G., Jentschel, M., Koster, U., Mutti, P., Regis, J. -M., Simpson, G., Soldner, T., Ur, C. A., Urban, W., Fraile, L. M., Lozeva, R., Belvito, B., Benzoni, G., Bruce, A., Carroll, R., Cieplicka-Orynczak, N., Crespi, F. C. L., Didierjean, F., Jolie, J., Korten, W., Kroll, T., Lalkovski, S., Mach, H., Marginean, N., Melon, B., Mengoni, D., Million, B., Nannini, A., Napoli, D., Olaizola, B., Paziy, V., Podolyakn, Zs., Regann, P. H., Saed-Samii, N., Szpak, B., Vedia, V.
Rok vydání: 2016
Předmět:
Druh dokumentu: Working Paper
DOI: 10.1016/j.physletb.2016.06.065
Popis: The gamma-ray decay of excited states of the one-valence-proton nucleus 133Sb has been studied using cold-neutron induced fission of 235U and 241Pu targets, during the EXILL campaign at the ILL reactor in Grenoble. By using a highly efficient HPGe array, coincidences between gamma-rays prompt with the fission event and those delayed up to several tens of microseconds were investigated, allowing to observe, for the first time, high-spin excited states above the 16.6 micros isomer. Lifetimes analysis, performed by fast-timing techniques with LaBr3(Ce) scintillators, reveals a difference of almost two orders of magnitude in B(M1) strength for transitions between positive-parity medium-spin yrast states. The data are interpreted by a newly developed microscopic model which takes into account couplings between core excitations (both collective and non-collective) of the doubly magic nucleus 132Sn and the valence proton, using the Skyrme effective interaction in a consistent way. The results point to a fast change in the nature of particle-core excitations with increasing spin.
Databáze: arXiv