Observation of excited states in the neutron-rich nucleus Br89

Low-spin excitations in Br89 populated in β− decay of Se89Rza̧ca‐Urban1, Sieja2, Czerwiński3 et al. 2022Phys. Rev. CSelf Cite0000View full textAdd to dashboardCite

“…The present work reports on the first study of excited levels in 89 Br populated in β − decay of 89 Se, complementing a series of recent investigations of Br isotopes [5][6][7][8][9][10]. It is also worth mentioning the search for the g 9/2 -proton-based excitation in 83 As in Ref.…”

“…3(c), which suggests that it is in a cascade The 130.2-keV line, reported in Ref. [10] as due to the ground-state transition in 89 Br, was first tentatively assigned to 89 Br by Rengan et al [22] who suggested that this transition may deexcite a level at 130.2 keV in 89 Br because no other γ more intense than the 130.2 keV transition was observed in the β − decay of 89 Br within a time interval of 2 s, and the shape of the 89 Br β − spectrum did not indicate any isomer in 89 Br with T 1/2 > 2 s.…”

“…with their daughters [21], and surrounding background such as 60 Co. Also seen are the strongest γ transitions from nuclei populated in β − decay of the A = 89 chain nuclei, though the strongest and the third strongest γ lines of 89 Br at 130.2 and 401.0 keV [10] are barely visible in this spectrum. The information on the strongest disturbing γ transitions and the strongest decays in the A = 89 chain, marked in the singles spectrum, is summarized in Table I.…”

“…In Fig. 3(c) we show a spectrum gated on the 130.2-keV line, reported as the strongest transition in 89 Br [10]. The number of counts in the spectrum is reduced by another two orders of magnitude and the 401.0-keV line dominates the spectrum.…”

“…It is also worth mentioning the search for the g 9/2 -proton-based excitation in 83 As in Ref. [11], which reports a tentative (9/2 + ) spin-parity for the level at 2779 keV, used for adjusting parameters of the shell model for the region and applied successfully to reproduce levels in Br [5][6][7][8][9][10] and Rb [12][13][14] isotopes. Quite large variations of the π f 5/2 → π g 9/2 s.p.…”