Speaker
Description
Historically, the simplest $\alpha$ decay is that of $^{212}$Po, which is conceptualized as a doubly magic $^{208}$Pb core with a valence $\alpha$ particle. For decades, this well-measured isotope has stood as the baseline for $\alpha$-decay models and comparison among other $\alpha$-emitting nuclei. However, a lighter region of $\alpha$ radioactivity was found in neutron-deficient tellurium and xenon isotopes resulting from the Z=50 and N=50 shell closures. Discovered by Macfarlane and Siivola, these decays are enhanced relative to $^{212}$Po, allowing the authors to coin the term “superallowed” $\alpha$ decay for the nuclei [1]. The self-conjugate decay of $^{104}$Te to $^{100}$Sn was then postulated to be the most enhanced $\alpha$ decay due to an increase in proton-neutron correlations. Two events of $^{104}$Te were measured by Auranen et al. Despite limited statistics, the authors placed an upper limit on the half-life via the decay chain of $^{108}$Xe [2]. This work reports an experiment at RIKEN RIBF using the fragmentation of $^{124}$Xe to produce the decay chain of $^{108}$Xe to $^{104}$Te to $^{100}$Sn [3]. In preparation for the short lifetime, a fast-response charged particle detector was utilized [4]. The half-life of $^{104}$Te was measured for the first time and is found to be the fastest ground-state $\alpha$-emitting nucleus known to date. Additionally, the deduced preformation demonstrates that the enhancement is greater for $^{104}$Te than for any other $\alpha$-decaying nucleus [3]. This presentation will compare the results with previous results from Auranen et al and numerous theoretical models.
[1] R. Macfarlane and A. Siivola, Phys. Rev. Lett. 14, 144 (1965)
[2] K. Auranen, et al. Phys. Rev. Lett. 121, 182501 (2018)
[3] I. Cox, et al. Nature, in Press (2026) https://doi.org/10.21203/rs.3.rs-7991707/v1
[4] Y. Xiao, et al. Phys. Rev. C 100, 034315 (2019)
This work was supported by US DOE No. DE-FG02-96ER40983 and NNSA No. DE-NA0003899