Nature(London) 629, 62 (2024)

A.Yamaguchi, Yu.Shigekawa, H.Haba, H.Kikunaga, K.Shirasaki, M.Wada, H.Katori

Laser spectroscopy of triply charged ²²⁹Th isomer for a nuclear clock

RADIOACTIVITY ²²⁹Th(IT); measured frequencies; deduced nuclear decay T_1/2, the hyperfine constants, reduced the uncertainty of the sensitivity of the nuclear clock to variations in the fine-structure constant by a factor of four with nuclear-state-selective laser spectroscopy.

doi: 10.1038/s41586-024-07296-1