Search for long-lived 2S muonic hydrogen in H2 gas
Abstract
We have searched for long-lived 2S muonic hydrogen (μ-p) in H2 gas at 0.8 atm. The state could be detected by observing delayed 1.9-keV 2P-->1S photons from collisionally quenched μ-p(2S). The observed upper limit (90% confidence level) for the fraction,f2S, of μ-p(2S) with lifetime τ2S in the gas in the range, 100<τ2S<1000 ns, is f2S<2%. Our results are consistent with the view that most of the μ-p(2S) have kinetic energies greater than the 0.3-eV threshold for the inelastic collision μ-p(2S)+H2-->μ-p(2P)+H2 and hence are rapidly quenched. We have also measured the relative Lyman line intensities in muonic hydrogen and muonic helium at 0.8 atm with solid-state detectors [Ge for μ-4He and Si(Li) for μ-p]. The results are (KαKtotal)μ-p=0.46+/-0.06, KαKtotal)μ-4He=0.76+/-0.04, (KβKtotal)μ-4He=0.04+/-0.02. These results imply that about 7.5% of μ-p atoms cascade to the 2S state.
- Publication:
-
Physical Review A
- Pub Date:
- March 1981
- DOI:
- 10.1103/PhysRevA.23.1152
- Bibcode:
- 1981PhRvA..23.1152E
- Keywords:
-
- Atomic Structure;
- Hydrogen Atoms;
- Muons;
- Nuclear Physics;
- Radiative Lifetime;
- Recombination Reactions;
- Atomic Energy Levels;
- Decay Rates;
- Fine Structure;
- Lyman Spectra;
- Particle Collisions;
- Particle Energy;
- Particle Interactions;
- Particle Theory;
- Photons;
- Protons;
- Radiation Counters;
- Radioactive Decay;
- X Rays;
- Nuclear and High-Energy Physics