2024/08/13 by Francesco Giacosa, Giacosa, Francesco, Krzysztof Kyzioł +1 · 1 citation
Physics and Astronomy · #Atomic and Subatomic Physics Research #Cold Atom Physics and Bose-Einstein Condensates #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #Quantum Physics (quant-ph) #Radioactive Decay and Measurement Techniques
paper · pdf · doi:10.48550/arxiv.2408.06905
openalex publication_date 2024/08/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We evaluate numerically the survival probability P(t) for the unstable 2P excited state of the hydrogen atom, which decays into the ground-state 1S emitting one photon (τ∼ 1.595 ns), thus extending the analytic study of Facchi and Pascazio, Physics Letters A 241 (1998). To this end, we first determine the analytic expression of the spectral function of the unstable state, which allows for an accurate evaluation of P(t). As expected, for short and long times P(t) shows deviations from the exponential law: a `Zeno' region occurs at extremely short times (up to ∼ 0.3 attosec, followed by a longer `anti-Zeno' domain (up to ∼ 50 attosec); at long times above 125 τ, the decay law scales as t-4.