Observation of a $μs$ isomer in ${134\atop{49}}$In$_{85}$: Proton-neutron coupling "southeast" of ${132\atop{50}}$Sn$_{82}

• Published in: Physical review. C 2019-07, Vol.100 (1)
• Main Authors: Phong, V. H., Lorusso, Giuseppe, Davinson, T., Estrade, A., Hall, O., Liu, J., Matsui, K., Montes, F., Nishimura, S., Boso, A., Regan, P. H., Shearman, R., Xu, Z. Y., Agramunt, J., Allmond, J. M., Ahn, D. S., Algora, A., Baba, H., Brewer, N. T., Bruno, C. G., Caballero-Folch, R., Calvino, F., Wolińska-Cichocka, M., Cortes, G., Dillmann, I., Domingo-Pardo, C., Gargano, A., Go, S., Griffin, C. J., Grzywacz, R. K., Harkness-Brennan, L., Isobe, T., Jungclaus, A., Kahl, D., Khiem, L. H., Kiss, G., Korgul, A., Kubono, S., Miernik, K., Morales, A. I., Nepal, N., Piersa, M., Podolyák, Zs, Rasco, B. C., Rykaczewski, K. P., Sakurai, H., Shimizu, Y., Stacener, D. W., Sumikama, T., Suzuki, H., Takeda, H., Tain, J. L., Tarifeño-Saldivia, A., Tolosa-Delgado, A., Vaquero, V., Woods, P. J., Yokoyama, R., Yuan, C.
• Format: Article
• Language: English
• Subjects: NUCLEAR PHYSICS AND RADIATION PHYSICS
• ISSN: 2469-9985; 2469-9993

In this paper, we report on the observation of a microsecond isomeric state in the single-proton-hole, three-neutron-particle nucleus 134In. The nuclei of interest were produced by in-flight fission of a 238U beam at the Radioactive Isotope Beam Factory at RIKEN. The isomer depopulates through a γ ray of energy 56.7(1) keV and with a half-life of $T_{1/2}$ = 3.5 (4) $μs$. Based on the comparison with shell-model calculations, we interpret the isomer as the $I^π$ = 5-member of the $π0g{-1\atop{9/2}}Ⓧv1f{3\atop{7/2}}$ multiplet, decaying to the $I^π$ = 7- ground state with a reduced-transition probability of $B (E$2; 5- $\rightarrow$ 7- = 0.53 (6) W. u. Observation of this isomer, and lack of evidence in the current work for a $I^π$ = 5- isomer decay in 132In, provides a benchmark of the proton-neutron interaction in the region of the nuclear chart “southeast” of 132Sn, where experimental information on excited states is sparse.