Is seniority a partial dynamic symmetry in the first vg(9/2) shell?

MORALES, A.; BENZONI, G.; WATANABE, H.; DE ANGELIS, G.; NISHIMURA, S.; CORAGGIO, L.; GARGANO, A.; ITACO, N.; OTSUKA, T.; TSUNODA, Y.; VAN ISACKER, R.; BROWNE, F.; Daido, R.; DOORNENBAL, R.; Fang, Y.; LORUSSO, G.; PATEL, Z.; RICE, S.; SINCLAIR, L.; SODERSTROM, P-A.; Sumikama, T.; VALIENTE-DOBON, J.; WU, J.; XU, Z.; Yagi, A.; YOKOYAMA, R.; BABA, H.; AVIGO, R.; GARROTE, F.; BLASI, N.; BRACCO, A.; BRUCE, A.; CAMERA, F.; CERUTI, S.; CRESPI, F.; DELATTRET, M.; DOMBRADI, Zs.; GOTTARDO, A.; ISOBE, T.; KOJOUHAROV, I.; KURZ, N.; KUTI, I.; Lalkovski, S.; MATSUI, K.; MELON, B.; MENGONI, D.; MIYAZAKI, T.; MODAMIO-HOYBJOR, V.; MOMIYAMA, S.; NAPOLI, D.; NIIKURA, M.; ORLANDI, R.; Podolyak, Zs.; Regan, P.; SAKURAI, H.; SAHIN, E.; SOHLER, D.; SCHAFFNER, H.; TANIUCHI, R.; TAPROGGE, J.; VAJTA, Zs.; WIELAND, O.; Yalcinkaya, MEHTAP

doi:10.1016/j.physletb.2018.04.049

Is seniority a partial dynamic symmetry in the first vg(9/2) shell?

MORALES A. I., BENZONI G., WATANABE H., DE ANGELIS G., NISHIMURA S., CORAGGIO L., ...Daha Fazla

PHYSICS LETTERS B, cilt.781, ss.706-712, 2018 (SCI-Expanded, Scopus)

Yayın Türü: Makale / Tam Makale
Cilt numarası: 781
Basım Tarihi: 2018
Doi Numarası: 10.1016/j.physletb.2018.04.049
Dergi Adı: PHYSICS LETTERS B
Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
Sayfa Sayıları: ss.706-712
İstanbul Üniversitesi Adresli: Evet

Özet

The low-lying structures of the midshell vg(9/2) Ni isotopes Ni-72 and Ni-74 have been investigated at the RIBF facility in RIKEN within the EURICA collaboration. Previously unobserved low-lying states were accessed for the first time following beta decay of the mother nuclei Co-72 and Co-74. As a result, we provide a complete picture in terms of the seniority scheme up to the first (8(+)) levels for both nuclei. The experimental results are compared to shell-model calculations in order to define to what extent the seniority quantum number is preserved in the first neutron g(9/2) shell. We find that the disappearance of the seniority isomerism in the (8(1)(+)) states can be explained by a lowering of the seniority-four (6(+)) levels as predicted years ago. For Ni-74, the internal de-excitation pattern of the newly observed (6(2)(+)) state supports a restoration of the normal seniority ordering up to spin J = 4. This property, unexplained by the shell-model calculations, is in agreement with a dominance of the single-particle spherical regime near Ni-78. (C) 2018 The Authors. Published by Elsevier B.V.