arXiv:2601.04341v1 Announce Type: new
Abstract: We report a high-precision calculation of the photodetachment energy of the hydrogen anion{normalsize{} }$text{H}^{-}$. The nonrelativistic bound-state energy is obtained using an exact three-body approach, and supplemented by leading relativistic, quantum-electrodynamic, finite-nuclear-size, and hyperfine corrections. Our result is $6083.06447(68),mathrm{cm}^{-1}$ for the detachment to the hydrogen ground-state hyperfine level $smash{(F=0)}$, which is 220 times more precise than the best experimental determination to date, $6082.99(15),mathrm{cm}^{-1}$, as reported by Lykke textit{et al. }Beyond their intrinsic interest, these results provide critical input for antihydrogen physics, where controlled photodetachment of $smash{bar{text{H}}^{+}}$ offers a path to producing ultracold antihydrogen (and its isotopes) for precision experiments. Corresponding calculations for the negative deuterium and tritium ions yield $6086.70676(68),mathrm{cm}^{-1}$ for $^{2}text{H}^{-}(F=1/2)$ and $6087.87924(68),mathrm{cm}^{-1}$ for $^{3}text{H}^{-}(F=0)$.