Measurement of the formation rate and the radiative decay of the muonic molecules (p mu He-3)* and (p mu He-4)*

摘要

Formation and decay of the (p mu(3)He)* and (p mu(4)He)* molecules have been studied in binary-gas mixtures of H-2 + He-3 and H-2 + He-4 at 30 K. The muon ground-state transfer rates from hydrogen to the two helium isotopes were extracted from the time distribution of the 7-keV decay x rays of the muonic hydrogen-helium molecules, measured with a Ge detector. The obtained transfer rates are lambda(p3He) = (0.46 +/- 0.15) x 10(8) s(-1) and lambda(p4He) = (0.42 +/- 0.07) x 10(8) s(-1). The radiative branching ratios of the decay of the (p mu(3)He)* and (p mu(4)He)* molecules were determined by comparing the yields of the Lyman series of muonic hydrogen with the one of the 7-keV line with charge-coupled-device detectors. The ratios are in agreement with theoretical predictions. Muon transfer from excited states of muonic hydrogen to both helium isotopes was also observed. [S1050-2947(98)07010-3]. [References: 31]