High-precision measurement of $^{215}$Po half-life via delayed-coincidence analysis
Università degli Studi dell’Aquila（阿奎拉大学）；INFN - Laboratori Nazionali del Gran Sasso（意大利国家核物理研究所-大萨索国家实验室）；Gran Sasso Science Institute（大萨索科学研究所）；INAF - Osservatorio Astrofisico di Torino（意大利国家天体物理研究所-都灵天文台）；INFN - Sezione di Torino（意大利国家核物理研究所-都灵分部）
Lorenzo Ascenzo, Melissa Hoda Baiocchi, Giovanni Benato, Yingjie Chu, Giuseppe Di Carlo, Andrea Molinario, Silvia Vernetto
We performed a high-precision study of the $^{215}$ Po $α$-decay using a LaBr$_3$ scintillating detector in a low-background environment. The $^{227}$Ac intrinsic contamination in the LaBr$_3$ crystal undergoes a decay chain, producing the intermediate pair of $^{219}$Rn$\rightarrow^{215}$Po$\rightarrow^{211}$Pb decays. The fast time response and good energy resolution of the detector allow for extracting the short half-life of $^{215}$Po from the time correlation of the two subsequent $α$-decays by using the delayed coincidence method. Thanks to high statistics and a comprehensive uncertainty assessment, we obtain the most precise half-life value to date of $^{215}$Po, corresponding to $1.77804\pm0.00091$(stat.)$\pm0.00067$(syst.) ms.
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