Observation of Large-Transverse-Momentum Muons Directly Produced by 300-GeV Protons

Abstract

We have observed muons produced directly in Cu and W targets by 300-GeV incident protons. We find a yield of muons which is approximately a constant fraction (0.8\ifmmode\cdot\else\textperiodcentered\fi{}${10}^{\ensuremath{-}4}$) of the pion yield for both positive and negative charges and for transverse momenta between 1.5 and 5.4 GeV/c.