Dimuon Production On Nuclear Targets

We have measured the production of $\ensuremath{\rho}+\ensuremath{\omega}$ and $J$ vector mesons, through their dimuon decay modes, by high-energy neutrons on nuclear targets at Fermilab. We determined the $A$ dependence to be ${A}^{0.62\ifmmode\pm\else\textpm\fi{}0.03}$ for $\ensuremath{\rho}+\ensuremath{\omega}$, ${A}^{0.93\ifmmode\pm\else\textpm\fi{}0.04}$ for $J$, and ${A}^{0.85\ifmmode\pm\else\textpm\fi{}0.05}$ for the continuum of dimuons between the $\ensuremath{\rho}+\ensuremath{\omega}$ and $J$ masses.