A novel measurement of the muon capture rate in liquid hydrogen by the lifetime technique

doi:10.1016/0375-9474(81)90416-4

Nuclear Physics A

Volume 352, Issue 3, 9 February 1981, Pages 365-378

https://doi.org/10.1016/0375-9474(81)90416-4 Get rights and content

Abstract

The muon nuclear capture rate by protons has been measured by comparing the lifetime τ_μ⁻ of negative muons stopped in liquid hydrogen with the lifetime τ_μ⁺ of positive muons. We get τ_μ⁻ = 2194.903 ± 0.066 ns and τ_μ⁺ = 2197.182 ± 0.121 ns. Taking into account also the previous determinations of τ_μ⁺, we present the updated determination of the muon lifetime, and correspondingly we obtain for the capture rate of muons from the pμp molecular ions the value λ_c = 460 ± 20 s⁻¹.

References (18)

G. Bardin et al.
Phys. Lett.
(1978)
S. Cohen et al.
Phys. Rev.
(1960)
M. Adam, G. Bardin, B. Coudou, J. Duclos, A. Godin, P. Leconte, A. Magnon, J. Martino, M. Maurier, A. Mougeot and D....J. Martino
Thèse de Docteur de 3e cycle
(1977)
J. Martino
Thèse de Docteur ès Sciences
(1980)
E. Zavattini
Muon physics II
G. Conforto et al.
Phys. Rev. Lett.
(1962)
A. Placci et al.
Nuovo Cim.
(1969)
A. Bertin et al.
Nuovo Cim. Lett.
(1972)
E.J. Bleser et al.
Phys. Rev. Lett.
(1962)
J.E. Rothberg et al.
Phys. Rev.
(1963)
A.Alberigi Quaranta et al.
Phys. Rev.
(1969)

There are more references available in the full text version of this article.

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^∗∗: We are grateful to A. Mougeot, who built the detectors and gave us his valuable technical assistance during the whole of the experiment, and to M. Caillat for various calculations. We thank A. Godin and his cryogenics group for designing and operating the target device. We are indebted to F. Netter and the machine operators for supplying the requested beam. On of us (E.Z.) thanks E. Gabathuler, Leader of the EP Division at CERN, for his support. Three of us (A.B., M.P., A.V.) wish to thank A. Zichichi, President of the INFN, for encouragement and support. On of us (A.R.) is grateful for partial support, to the Deutsches Bundesministerium für Forschung und Technologie.

^∗: Permanent address: Institut für Kernphysik, Technische Hochschule Darmstadt, Germany.

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A novel measurement of the muon capture rate in liquid hydrogen by the lifetime technique

Abstract

Phys. Lett.

Phys. Rev.

Thèse de Docteur de 3e cycle

Thèse de Docteur ès Sciences

Muon physics II

Phys. Rev. Lett.

Nuovo Cim.

Nuovo Cim. Lett.

Phys. Rev. Lett.

Phys. Rev.

Phys. Rev.