Abstract
Background: -decay spectroscopy provides valuable information on exotic nuclei and a stringent test for nuclear theories beyond the stability line.
Purpose: To search for new -delayed protons and rays of to investigate the properties of excited states.
Method: decays were measured by using the Gaseous Detector with Germanium Tagging system at the National Superconducting Cyclotron Laboratory. The protons and rays emitted in the decay were detected simultaneously. A Monte Carlo method was used to model the Doppler broadening of -ray lines caused by nuclear recoil from proton emission. Shell-model calculations using two newly developed universal sd-shell Hamiltonians were performed.
Results: The most precise half-life to date has been determined. A new proton branch at 724(4) keV and new proton--ray coincidences have been identified. Three -ray lines and eight -ray lines are observed for the first time in decay. The first measurement of the -delayed -ray intensities through the unbound states is reported. All the bound states of are observed to be populated in the decay of . Several inconsistencies between the previous measurements have been resolved, and new information on the level scheme is provided. An enhanced decay scheme has been constructed and compared to the mirror decay of and the shell-model calculations.
Conclusions: The measured excitation energies, -ray and proton branchings, log values, and Gamow-Teller transition strengths for the states of populated in the decay of are in good agreement with the shell-model calculations, offering gratifyingly consistent insights into the fine nuclear structure of .
1 More- Received 10 September 2020
- Accepted 22 December 2020
DOI:https://doi.org/10.1103/PhysRevC.103.014322
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