Measurement of Muon Capture on the Proton to 1% Precision and Determination of the Pseudoscalar Coupling g{sub P}
The MuCap experiment at the Paul Scherrer Institute has measured the rate Λ{sub 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, ultrapure hydrogen gas. Cylindrical wire chambers and a segmented scintillator barrel detected electrons from muon decay. Λ{sub S} is determined from the difference between the μ{sup -} disappearance rate in hydrogen and the free muon decay rate. The result is based on the analysis of 1.2×10{sup 10} μ{sup -} decays, from which we extract the capture rate Λ{sub S} =(714.9±5.4{sub stat} ±5.1{sub syst} )s{sup -1} and derive the proton’s pseudoscalar coupling g{sub P} (q{sup 2}{sub 0} =-0.88m{sup 2}{sub μ} )=8.06±0.55 .
- Research Organization:
- University of California at Berkeley
- Sponsoring Organization:
- USDOE
- Contributing Organization:
- MuCaP Collaboration
- DOE Contract Number:
- FG02-00ER41129
- OSTI ID:
- 1126258
- Report Number(s):
- Final Technical Report
- Journal Information:
- Physical Review Letters, Vol. 110; ISSN 0031-9007
- Publisher:
- American Physical Society (APS)
- Country of Publication:
- United States
- Language:
- English
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