Measurement of Muon Capture on the Proton to 1% Precision and Determination of the Pseudoscalar Coupling g{sub P}

Journal Article · Tue Jan 01 04:00:00 EST 2013 · Physical Review Letters

DOI:https://doi.org/10.1103/PhysRevLett.110.012504· OSTI ID:1126258

Freedman, Stuart ^[1]; Banks, Tom

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1. UC Berkeley

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, Journal Name: Physical Review Letters Vol. 110; ISSN 0031-9007
• Publisher: American Physical Society (APS)
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS