An experiment to measure the muon nuclear capture rate in ultrapure gaseous hydrogen (8 atm, 293 K) has been performed using a special target in which a system of gas proportional counters, working with the pure hydrogen of the target itself, were operating. Neutrons from the capture reactions were detected using a scintillator-counter technique, and the gamma-ray background was eliminated by pulse-shape discrimination. The working conditions ensured that the captures were taking place in the mu-p atomic systems in a singlet total-spin state. The experimental result is Lambda_expt = (651 +- 57) 1/sec, which has to be compared with the theoretical rate Lambda_s,theor = (626 +- 26) 1/sec. From the experimental capture rate, and within the framework of the currently accepted theory, we have obtained for the induced pseudoscalar coupling constant g_p = (-7.3 +- 3.7) g_v. The results of the present experiment are analyzed, together with the results obtained from stopping negative muons in liquid hydrogen.
Muon capture in gaseous hydrogen
DALPIAZ, Pietro;
1969
Abstract
An experiment to measure the muon nuclear capture rate in ultrapure gaseous hydrogen (8 atm, 293 K) has been performed using a special target in which a system of gas proportional counters, working with the pure hydrogen of the target itself, were operating. Neutrons from the capture reactions were detected using a scintillator-counter technique, and the gamma-ray background was eliminated by pulse-shape discrimination. The working conditions ensured that the captures were taking place in the mu-p atomic systems in a singlet total-spin state. The experimental result is Lambda_expt = (651 +- 57) 1/sec, which has to be compared with the theoretical rate Lambda_s,theor = (626 +- 26) 1/sec. From the experimental capture rate, and within the framework of the currently accepted theory, we have obtained for the induced pseudoscalar coupling constant g_p = (-7.3 +- 3.7) g_v. The results of the present experiment are analyzed, together with the results obtained from stopping negative muons in liquid hydrogen.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
