Muon capture rates from precision measurements of the muon disappearance

Abstract

In a typical experiment the nuclear μ-capture rate is determined from measurements of the time constant of the muon decay exponential in a target. We propose a new approach for the evaluation of the μ-capture rate, which is based on direct measurements of the μ^- disappearance rate in the target. Considering, as an example, the reaction of μ-capture on proton, we demonstrate that measurements of the μ^- disappearance at different values of the hydrogen gas pressure in the target could be used to avoid a pressure-dependent correction and determine the "vacuum" μp -> νn reaction rate with accuracy better than 10^{-2} after extrapolation to zero gas density. The proposed method could be used to perform precision measurements of the μ^- capture rate on different types of nuclei in one experiment.

arXiv comment7 pp, 3 figs, title modified, fig. 3 and typos corrected, refs. added