Investigation of charge transfer from excited muonic hydrogen atoms to argon

Abstract

A method is proposed for investigating muon transfer from excited muonic hydrogen atoms to an element $Z>2$, and is applied to argon measurements. It makes use of a comparison between the muonic x-ray intensity patterns of the Lyman series of this element measured in mixtures with and without hydrogen. The analysis of the data taken in two gas mixtures H${}_{2}$ + Ar at 15 bar with argon concentrations of 2% (0.3%), yields consistent results. In both mixtures, two thirds of the prompt argon x rays proceed from transfer from excited $\ensuremath{\mu}{p}^{*}$ states. The Coulomb capture ratio determined in both mixtures yields a mean value of $A$(H${}_{2}$,Ar) = 0.21(2), and agrees with the corresponding pionic ratio.