Author(s): Shulin Tang, Tao Wan, Yibin Qian, Chong Qi, Ramon A. Wyss, Roberto J. Liotta, Dong Bai, Bo Zhou, and Zhongzhou Ren The simultaneous emission of two $α$ particles—double-$α$ decay—represents a long-predicted but unobserved mode of nuclear radioactivity. Here, we formulate this process as a genuine three-body problem within the hyperspherical coordinate framework and evaluate decay probabilities by numerically sol… [Phys. Rev. Lett. 136, 172503] Published Fri May 01, 2026