Production of Prompt Muons by the Interaction of 28-GeV Protons

Abstract

Analyses of measurements of muons produced directly, in the forward direction, by the interaction of 28-GeV protons with uranium show that the muon/pion production ratio for negative particles is 13\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}5}$ for 11.6-GeV particles, 2.6\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}5}$ at 20.3 GeV, 1.3\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}5}$ at 23.5 GeV, and 7.0\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}6}$ at 25 GeV. The largest ratio is similar to ratios measured at higher energies and large transverse momenta and none of the ratios are easily explained in terms of conventional mechanisms.