Measurement of the Reaction $^{12}C(ν_μ,μ^-) X$ Near Threshold

Abstract

The reaction $^{12}C(ν_μ,μ^-) X$ has been measured near threshold using a $π^+$ decay-in-flight $ν_μ$ beam from the Los Alamos Meson Physics Facility and a massive liquid scintillator neutrino detector (LSND). In the energy region $123.7 < E_ν< 280$ MeV, the measured spectral shape is consistent with that expected from the Fermi Gas Model. However, the measured flux-averaged inclusive cross section ($(8.3 \pm 0.7 stat. \pm 1.6 syst.) \times 10^{-40} cm^2$) is more than a factor of 2 lower than that predicted by the Fermi Gas Model and by a recent random phase approximation calculation.