Measurement of the Positive Muon Lifetime and Determination of the Fermi Constant to Part-per-Million Precision

Journal Article · Fri Jan 28 04:00:00 EST 2011 · Physical Review Letters

DOI:https://doi.org/10.1103/PHYSREVLETT.106.041803· OSTI ID:21532259

Webber, D M; Chitwood, D B; Crnkovic, J; Debevec, P T; Hertzog, D W; Kammel, P; Kiburg, B; Kizilgul, S; Kunkle, J; McNabb, R; Winter, P; Wolfe, B ^[1]; Tishchenko, V; Battu, S; Dhamija, S; Gorringe, T P; Rath, S ^[2]; Peng, Q; Carey, R M; Earle, W ^[3]

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1. Department of Physics, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801 (United States)
2. Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506 (United States)
3. Department of Physics, Boston University, Boston, Massachusetts 02215 (United States)

We report a measurement of the positive muon lifetime to a precision of 1.0 ppm; it is the most precise particle lifetime ever measured. The experiment used a time-structured, low-energy muon beam and a segmented plastic scintillator array to record more than 2x10{sup 12} decays. Two different stopping target configurations were employed in independent data-taking periods. The combined results give {tau}{sub {mu}}{sup +}(MuLan)=2 196 980.3(2.2) ps, more than 15 times as precise as any previous experiment. The muon lifetime gives the most precise value for the Fermi constant: G{sub F}(MuLan)=1.166 378 8(7)x10{sup -5} GeV{sup -2} (0.6 ppm). It is also used to extract the {mu}{sup -}p singlet capture rate, which determines the proton's weak induced pseudoscalar coupling g{sub P}.

• OSTI ID: 21532259
• Journal Information: Physical Review Letters, Journal Name: Physical Review Letters Journal Issue: 4 Vol. 106; ISSN 0031-9007; ISSN PRLTAO
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
ACCURACY
BARYONS
BASIC INTERACTIONS
BEAMS
CAPTURE
COUPLING
DECAY
ELEMENTARY PARTICLES
FERMI INTERACTIONS
FERMIONS
HADRONS
INTERACTIONS
LEPTON BEAMS
LEPTONS
LIFETIME
MUON BEAMS
MUONS
MUONS MINUS
NUCLEONS
PARTICLE BEAMS
PROTONS
WEAK INTERACTIONS