Early Signal of Emerging Nuclear Collectivity in Neutron-Rich Sb 129

Autor: Gray, T. J., Allmond, J. M., Stuchbery, A. E., Yu, C. -H., Baktash, C., Gargano, A., Galindo-Uribarri, A., Radford, D. C., Batchelder, J. C., Beene, J. R., Bingham, C. R., Coraggio, L., Covello, A., Danchev, M., Gross, C. J., Hausladen, P. A., Itaco, N., Krolas, W., Liang, J. F., Padilla-Rodal, E., Pavan, J., Stracener, D. W., Varner, R. L.
Přispěvatelé: Gray, T. J., Allmond, J. M., Stuchbery, A. E., Yu, C. -H., Baktash, C., Gargano, A., Galindo-Uribarri, A., Radford, D. C., Batchelder, J. C., Beene, J. R., Bingham, C. R., Coraggio, L., Covello, A., Danchev, M., Gross, C. J., Hausladen, P. A., Itaco, N., Krolas, W., Liang, J. F., Padilla-Rodal, E., Pavan, J., Stracener, D. W., Varner, R. L.
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Popis: Radioactive $^{129}$Sb, which can be treated as a proton plus semi-magic $^{128}$Sn core within the particle-core coupling scheme, was studied by Coulomb excitation. Reduced electric quadrupole transition probabilities, $B(E2)$, for the $2^+$ $\times$ $\pi g_{{7/2}}$ multiplet members and candidate $\pi d_{{5/2}}$ state were measured. The results indicate that the total electric quadrupole strength of $^{129}$Sb is a factor of 1.39(11) larger than the $^{128}$Sn core, which is in stark contrast to the expectations of the empirically successful particle-core coupling scheme. Shell-model calculations performed with two different sets of nucleon-nucleon interactions suggest that this enhanced collectivity is due to constructive quadrupole coherence in the wavefunctions stemming from the proton-neutron residual interactions, where adding one nucleon to a core near a double-shell closure can have a pronounced effect. The enhanced electric quadrupole strength is an early signal of the emerging nuclear collectivity that becomes dominant away from the shell closure.
Comment: Accepted, Physical Review Letters
Databáze: OpenAIRE