$\beta^-$ decay of neutron-rich $^{45}$Cl at magic number N=28
| Autor: | Bhattacharya, Soumik, Tripathi, Vandana, Tabor, S. L., Volya, A., Bender, P. C., Benetti, C., Carpenter, M. P., Carroll, J. J., Chester, A., Chiara, C. J., Childers, K., Clark, B. R., Crider, B. P., Harke, J. T., Liddick, S. N., Lubna, R. S., Luitel, S., Longfellow, B., Mogannam, M. J., Ogunbeku, T. H., Perello, J., Richard, A. L., Rubino, E., Saha, S., Shehu, O. A., Unz, R., Xiao, Y., Zhu, Yiyi |
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| Rok vydání: | 2023 |
| Předmět: | |
| Druh dokumentu: | Working Paper |
| Popis: | Results from the study of $\beta^-$-decay of $^{45}$Cl, produced in the fragmentation of a 140-MeV/u $^{48}$Ca beam, are presented. The half-life for $^{45}$Cl $\beta$-decay is measured to be 513(36) ms. The $\beta^-$ and $\beta^- 1n$ decay of $^{45}$Cl populated excited states in $^{45,44}$Ar, respectively. On the basis of $\gamma$-ray singles and $\gamma$-$\gamma$ coincidence data, decay schemes for the two daughter nuclei have been established. They are compared with shell model calculations using the FSU interaction. The low-lying negative parity states for $^{45}$Ar are well described by a single particle (neutron) occupying orbitals near the Fermi surface, whereas neutron excitations across the $N = 20$ shell gap are needed to explain the positive-parity states which are expected to be populated in allowed Gamow-Teller $\beta$-decay of $^{45}$Cl. The highest $\beta$-feeding to the 5/2$^+$ state in $^{45}$Ar from the ground state of $^{45}$Cl points towards a 3/2$^+$ spin-parity assignment of the ground state of the parent over the other possibility of 1/2$^+$. The high Q$_{\beta^-}$ value of $^{45}$Cl decay allows for the population of $1p1h$ states above the neutron separation energy in $^{45}$Ar leading to positive parity states of $^{44}$Ar being populated by removal of one neutron from the $sd$ shell. The spin-parities of the excited levels in $^{44}$Ar are tentatively assigned for the first time by comparison with the shell model calculations. The 2978~keV level of $^{44}$Ar is identified as the excited 0$^+$ level which could correspond to a different configuration from the ground state. Comment: 11 pages, 10 figures |
| Databáze: | arXiv |
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