Production of Dimuons in 16-GeV/cπpInteractions and the Observation of a Low-Mass Continuum of Unfamiliar Origin

A clear, prompt dimuon signal has been observed in a low-statistics streamer-chamber experiment with 16-GeV/c $\ensuremath{\pi}p$ interactions. The good mass resolution makes it possible to identify the contributions from $\ensuremath{\rho}$ and $\ensuremath{\omega}$ decays and $\ensuremath{\eta}$ and $\ensuremath{\omega}$ Dalitz decays. An excess of events is observed in the mass region \ensuremath{\sim}400-600 MeV which is not accounted for by the above-mentioned decays.