Pohl R, Daniel H, Hartmann FJ, Hauser P, Kottmann F, Markushin VE, Mühlbauer M, Petitjean C, Schott W, Taqqu D, Wojciechowski-Grosshauser P. Observation of long-lived muonic hydrogen in the 2S state.
PHYSICAL REVIEW LETTERS 2006;
97:193402. [PMID:
17155627 DOI:
10.1103/physrevlett.97.193402]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2006] [Indexed: 05/12/2023]
Abstract
The kinetic energy distribution of ground state muonic hydrogen atoms mup(1S) is determined from time-of-flight spectra measured at 4, 16, and 64 hPa H2 room-temperature gas. A 0.9 keV component is discovered and attributed to radiationless deexcitation of long-lived mu p(2S) atoms in collisions with H2 molecules. The analysis reveals a relative population of about 1%, and a pressure-dependent lifetime (e.g., 30.4 +21.4/-9.7 ns at 64 hPa) of the long-lived mu p(2S) population, equivalent to a 2S quench rate in mu p(2S)+H2 collisions of 4.4 +2.1/-1.8 x 10(11) s(-1) at liquid-hydrogen density.
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