Neutron-proton multiplets in the nucleusBr88

Penning-trap-assisted study of excitations in Br88 populated in β decay of Se88Czerwiński1, Sieja2, Rza̧ca‐Urban3 et al. 2017Phys. Rev. CSelf Cite74102View full textAdd to dashboardCite

“…All the γ lines marked in the spectrum were assigned to 88 Br, except the 775.2-keV transition which belongs to its daughter nucleus, 88 Kr. In the present work we confirm and extend the low-spin scheme of excited levels in 88 Br, reported in the prompt-γ measurement of 235 U fission induced by neutrons [2]. Compared to the previous β-decay measurement [13], we found 15 new levels and 44 new γ transitions populated following the β decay of 88 Se.…”

“…Of particular interest is the study of the development of collectivity close to 78 Ni, which may affect the r-process path by, for example, increasing nuclear binding energies. Such collective effects have been observed at N = 52 and N = 53 in our recent studies of 86 Se, 87 Se, 88 Br, and 90 Rb [1][2][3][4][5] and reproduced well by shell-model calculations [6]. One of the expected consequences of this collectivity is additional low-energy, low-spin levels at N = 53 as compared to N = 51 isotones, expected due to the (νd 3 5/2 ) j , seniority-3 multiplet.…”

“…We also reported seven low-energy, low-spin levels interpreted as members of the πp 3/2 ν(d 5/2 ) 3 and πf −1 5/2 ν(d 5/2 ) 3 multiplets. The number of observed levels is lower than expected, when the (νd 3 5/2 ) j seniority-3 multiplet is considered (its presence in 88 Br is confirmed at higher excitation energies, where the πg 9/2 (d 5/2 ) 3 multiplet is observed [2]). The reason is probably the yrast-type population mechanism in fission, which does not reveal the non-yrast members of the two multiplets.…”

“…In the study of 235 U fission induced by cold neutrons [2] we proposed a spin and parity (1 − ) for the ground state of 88 Br, changing the (2 − ) assignment adopted in the compilation [7]. We also reported seven low-energy, low-spin levels interpreted as members of the πp 3/2 ν(d 5/2 ) 3 and πf −1 5/2 ν(d 5/2 ) 3 multiplets.…”

“…[1][2][3]. The exploration of this region is motivated by the interest in elucidating the structure of the very neutron-rich nuclei, located near the astrophysical r-process path and close to 78 Ni, which is expected to be a doubly magic core.…”