Measurement of muon capture on the proton to 1% precision and determination of the pseudoscalar coupling gP.
نویسندگان
چکیده
The MuCap experiment at the Paul Scherrer Institute has measured the rate Λ(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(S) is determined from the difference between the μ(-) disappearance rate in hydrogen and the free muon decay rate. The result is based on the analysis of 1.2 × 10(10) μ(-) decays, from which we extract the capture rate Λ(S) = (714.9 ± 5.4(stat) ± 5.1(syst)) s(-1) and derive the proton's pseudoscalar coupling g(P)(q(0)(2) = -0.88 m(μ)(2)) = 8.06 ± 0.55.
منابع مشابه
Muon capture on the proton and deuteron
By measuring the lifetime of the negative muon in pure protium (H), the MuCap experiment determines the rate of muon capture on the proton, from which the proton’s pseudoscalar coupling gp may be inferred. A precision of 15% for gp has been published; this is a step along the way to a goal of 7%. This coupling can be calculated precisely from heavy baryon chiral perturbation theory and therefor...
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a * on behalf of the µLan † and µCap ‡ Collaborations. The µLan experiment at the Paul Scherrer Institute will measure the lifetime of the positive muon with a precision of 1 ppm, giving a value for the Fermi coupling constant GF at the level of 0.5 ppm. Meanwhile, by measuring the observed lifetime of the negative muon in pure hydrogen, the µCap experiment will determine the rate of muon captu...
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عنوان ژورنال:
- Physical review letters
دوره 110 1 شماره
صفحات -
تاریخ انتشار 2013