Rare $^{40}$K decay with implications for fundamental physics and geochronology
| Autor: | Stukel, M., Hariasz, L., Di Stefano, P. C. F., Rasco, B. C., Rykaczewski, K. P., Brewer, N. T., Stracener, D. W., Liu, Y., Gai, Z., Rouleau, C., Carter, J., Kostensalo, J., Suhonen, J., Davis, H., Lukosi, E. D., Goetz, K. C., Grzywacz, R. K., Mancuso, M., Petricca, F., Fijałkowska, A., Wolińska-Cichocka, M., Ninkovic, J., Lechner, P., Ickert, R. B., Morgan, L. E., Renne, P. R., Yavin, I. |
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| Rok vydání: | 2022 |
| Předmět: | |
| Zdroj: | Physical Review Letters, 131-052503 (2023) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevLett.131.052503 |
| Popis: | Potassium-40 is a widespread, naturally occurring isotope whose radioactivity impacts subatomic rare-event searches, nuclear structure theory, and estimated geological ages. A predicted electron-capture decay directly to the ground state of argon-40 has never been observed. The KDK (potassium decay) collaboration reports strong evidence of this rare decay mode. A blinded analysis reveals a non-zero ratio of intensities of ground-state electron-captures ($I_{\text{EC}^0}$) over excited-state ones ($I_\text{EC*}$) of $ I_{\text{EC}^0} / I_\text{EC*} = 0.0095 \stackrel{\text{stat}}{\pm} 0.0022 \stackrel{\text{sys}}{\pm} 0.0010 $ (68% C.L.), with the null hypothesis rejected at 4$\sigma$. In terms of branching ratio, this signal yields $I_{\text{EC}^0} = 0.098\% \stackrel{\text{stat}}{\pm} 0.023\% \stackrel{\text{sys}}{\pm} 0.010\% $, roughly half of the commonly used prediction, with consequences for various fields [L. Hariasz et al., companion paper, DOI: 10.1103/PhysRevC.108.014327]. Comment: This is a companion paper to Hariasz et al (KDK collaboration) "Evidence for ground-state electron capture of ${}^{40}$K" [arXiv:2211.10343; DOI: 10.1103/PhysRevC.108.014327]. As such, both texts share some figures and portions of text. This version includes the journal DOI |
| Databáze: | arXiv |
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