Muon capture by 3He nuclei followed by proton and deuteron production

Abstract

The paper describes an experiment aimed at studying muon capture by ${}^{3}\mathrm{He}$ nuclei in pure ${}^{3}\mathrm{He}$ and $\mathrm{D}_2 + {}^{3}\mathrm{He}$ mixtures at various densities. Energy distributions of protons and deuterons produced via $μ^-+{}^{3}\mathrm{He}\to p+n+n + ν_{μ}$ and $μ^-+{}^{3} \mathrm{He} \to d+n + ν_μ$ are measured for the energy intervals $10 - 49$ MeV and $13 - 31$ MeV, respectively. Muon capture rates, $λ_\mathrm{cap}^p (ΔE_p)$ and $λ_\mathrm{cap}^d (ΔE_d)$ are obtained using two different analysis methods. The least--squares methods gives $λ_\mathrm{cap}^p = (36.7\pm 1.2) {s}^{- 1}$, $λ_\mathrm{cap}^d = (21.3 \pm 1.6) {s}^{- 1}$. The Bayes theorem gives $λ_\mathrm{cap}^p = (36.8 \pm 0.8) {s}^{- 1}$, $λ_\mathrm{cap}^d = (21.9 \pm 0.6) {s}^{- 1}$. The experimental differential capture rates, $dλ_\mathrm{cap}^p (E_p) / dE_p $ and $ dλ_\mathrm{cap}^d (E_d) / dE_d$, are compared with theoretical calculations performed using the plane--wave impulse approximation (PWIA) with the realistic NN interaction Bonn B potential. Extrapolation to the full energy range yields total proton and deuteron capture rates in good agreement with former results.

17 pages, 13 figures, accepted for publication in PRA