Muonic hydrogen cascade time and lifetime of the short-lived $2S$ state

Abstract

Metastable $2S$ muonic-hydrogen atoms undergo collisional $2S$-quenching, with rates which depend strongly on whether the $\mu p$ kinetic energy is above or below the $2S\to 2P$ energy threshold. Above threshold, collisional $2S\to 2P$ excitation followed by fast radiative $2P\to 1S$ deexcitation is allowed. The corresponding short-lived $\mu p(2S)$ component was measured at 0.6 hPa ${\mathrm{H}}_2$ room temperature gas pressure, with lifetime ${\tau }_{2S}^{\mathrm{short}}=165_{-29}^{+38}$ ns (i.e., ${\lambda }_{2S}^{\mathrm{quench}}=7.9_{-1.6}^{+1.8}\times 10^{12}{\mathrm{s}}^{-1}$ at liquid-hydrogen density) and population ${\epsilon }_{2S}^{\mathrm{short}}=1.70_{-0.56}^{+0.80}$ % (per $\mu p$ atom). In addition, a value of the $\mu p$ cascade time, $T_{\mathrm{cas}}^{\mu p}=(37\pm 5)$ ns, was found.

4 pages, 3 figures

References in corpus (4)

• Theory of Light Hydrogenlike Atoms
• Collisional deexcitation of exotic hydrogen atoms in highly excited states. II. Cascade calculations
• Observation of Long-Lived Muonic Hydrogen in the 2S State
• Planar LAAPDs: Temperature Dependence, Performance, and Application in Low Energy X-ray Spectroscopy

Cited by in corpus (5)

• Lamb Shift in Muonic Hydrogen. II. Analysis of the Discrepancy of Theory and Experiment
• Lifetime and population of the 2S state in muonic protium and deuterium
• The isotopic effects in the scattering and the kinetics of the atomic cascade
• Collision-induced radiative quenching and other disintegration modes of the $2S$ state of muonic hydrogen and deuterium atoms
• Radiative decay of muonic molecules in resonance states