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arXiv · 1210.6545

Measurement of Muon Capture on the Proton to 1% Precision and Determination of the Pseudoscalar Coupling g_P

V. A. Andreev·T. I. Banks·R. M. Carey·T. A. Case·S. M. Clayton·K. M. Crowe·J. Deutsch·J. Egger·S. J. Freedman·V. A. Ganzha·T. Gorringe·F. E. Gray·D. W. Hertzog·M. Hildebrandt·P. Kammel·B. Kiburg·S. Knaack·P. A. Kravtsov·A. G. Krivshich·B. Lauss·K. R. Lynch·E. M. Maev·O. E. Maev·F. Mulhauser·C. Petitjean·G. E. Petrov·R. Prieels·G. N. Schapkin·G. G. Semenchuk·M. A. Soroka·V. Tishchenko·A. A. Vasilyev·A. A. Vorobyov·M. E. Vznuzdaev·P. Winter
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Abstract

The MuCap experiment at the Paul Scherrer Institute has measured the rate L_S of muon capture from the singlet state of the muonic hydrogen atom to a precision of 1%. A muon beam was stopped in a time projection chamber filled with 10-bar, ultra-pure hydrogen gas. Cylindrical wire chambers and a segmented scintillator barrel detected electrons from muon decay. L_S is determined from the difference between the mu- disappearance rate in hydrogen and the free muon decay rate. The result is based on the analysis of 1.2 10^10 mu- decays, from which we extract the capture rate L_S = (714.9 +- 5.4(stat) +- 5.1(syst)) s^-1 and derive the proton's pseudoscalar coupling g_P(q^2_0 = -0.88 m^2_mu) = 8.06 +- 0.55.

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V. A. Andreev, T. I. Banks, R. M. Carey, T. A. Case, S. M. Clayton, K. M. Crowe, J. Deutsch, J. Egger, S. J. Freedman, V. A. Ganzha, T. Gorringe, F. E. Gray, D. W. Hertzog, M. Hildebrandt, P. Kammel, B. Kiburg, S. Knaack, P. A. Kravtsov, A. G. Krivshich, B. Lauss, K. R. Lynch, E. M. Maev, O. E. Maev, F. Mulhauser, C. Petitjean, G. E. Petrov, R. Prieels, G. N. Schapkin, G. G. Semenchuk, M. A. Soroka, V. Tishchenko, A. A. Vasilyev, A. A. Vorobyov, M. E. Vznuzdaev, P. Winter. 2012-10-24. Measurement of Muon Capture on the Proton to 1% Precision and Determination of the Pseudoscalar Coupling g_P. https://doi.org/10.1103/physrevlett.110.012504

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