A Measurement of the Weak Pseudosclar Coupling by Radiative Muon Capture in Hydrogen
department or school: Non UBC
data provider: DSpace
contributor: TRIUMF
creator: McDonald, Steven Campbell
issued: 2019-03-06T18:01:12Z
issued: 1993-12
description: This thesis reports the first measurement of the radiative muon capture photon energy spectrum from hydrogen, performed at TRIUMF. The partial branching ratio for photons greater than 58 Me V is measured using a large solid-angle photon pair spectrometer. With this measurement, the strength of the weak pseudoscalar coupling, gp, of the weak hadronic current for the nucleon has been obtained. This was determined by comparing the measured photon rate with the most recent relativistic calculation of Fearing and Beder which included the affect of the Δ(1232) nucleon resonance in the process. When a muon is captured by a proton at densities of liquid hydrogn, it occurs predominantly from one of two states, the ortho molecular state and the para molecular state. The muon capture probability varies considerably between the two, with the ortho state the dominant. At present there is some contention over the rate of transfer between these two states, this rate, λ₀p, can effect the total rate of capture. This rate must be known for an accurate determination of gp· Consequently, two values of gp have been obtained. One, using the measured ortho to para transition rate, λ₀p = 4.1 x 10⁴ giving a value of gp = 11.2 ± 2.5, approximately 34% higher then the Goldberger-Treiman prediction. The corresponding partial branching ratio for photons greater than 58 MeV was measured to be 1.80 ± 0.3 x 10-⁸. The second value was obtained using the theoretical prediction for the transfer rate to the ground para state, λ₀p = 7.1 x 10⁴. This gives a value of gp = 10.5 ± 2.2 with the equivalent partial branching ratio of 1.82 ± 0.3 x 10-⁸, 26% larger than the PCAC prediction.
aggregated CHO: https://circle.library.ubc.ca/rest/handle/2429/68497
note: A MEASUREMENT OF THE WEAK PSEUDOSCALAR COUPLING BY RADIATIVE MUON CAPTURE IN HYDROGEN By STEVEN CAMPBELL McDONALD B. Sc. (Hons.) University of Melbourne, 1987 A THESIS SUBMITTED FOR THE DEGREE OF DOCTOR OF PHILOSOPHY ID THE FACULTY OF SCIENCE SCHOOL OF PHYSICS THE UNIVERSITY OF MELBOURNE DECEMBER 1993 TRIUMF LIBRARY JUL 1 2 1994 The work presented in this thesis was not performed by any other person, except where acknowledged. The material in this manuscript has not been submitted pre-viously, in whole or part, in respect of any other academi c award. All of the work has been carried out since the official commencement date of the program. Where this thesis contains material previously published or written by another person, due reference is made in the text. Signed: Date: lll Abstract This thesis reports the first measurement of the radiati ve muon capture photon energy spectrum from hydrogen, performed at TRIUMF. The partial branching ratio for photons greater than 58 Me V is measured using a large solid-angle photon pair spectrometer. With this measurement, the strength of the weak pseudoscalar coupling, gp, of the weak hadronic current for the nucleon has been obtained. This was determined by comparing the measured photon rate with the most recent relativistic calculation of Fearing and Beder which included the affect of the ~(1232) nucleon resonance in the process. When a muon is captured by a proton at densities of liquid hydrogn, it occurs predominantly from one of two states, the ortho molecular state and the para molec-ular state. The muon capture probability varies considerably between the two, with the ortho state the dominant. At present there is some contention over the rate of transfer between these two states, this rate, >.0p, can effect the total rate of capture. This rate must be known for an accurate determination of 9p· Consequently, two values of gp have been obtained. One, using the measured ortho to para transition rate, >.0 P = 4.1 x 104 givin…
has type: Thesis/Dissertation
is shown at: 10.14288/1.0376648
language: eng
peer review status: Unreviewed
provider: Vancouver : University of British Columbia Library
publisher: TRIUMF
rights: Attribution-NonCommercial-NoDerivatives 4.0 International
rights URI: http://creativecommons.org/licenses/by-nc-nd/4.0/
scholar level: Graduate
type: Text
identifier URI: http://hdl.handle.net/2429/68497