Dimuon Production by Neutrons

Abstract

A very narrow resonance with a mass of 3.1 GeV/${\mathit{c}}^2$ is observed in the reaction $n+\mathrm{Be}\to {\mu }^{+}+{\mu }^{-}+X$. The total cross section for this process, as well as its ${P_{\perp }}^2$ and $x$ distribution, are given.