We test quantitatively the hypothesis that the Fermilab anomaly in inclusive $\overline{v}N\to {\mu }^{+}X$ distributions comes from charm production via intermediate vector ($V$) and axial-vector ($A$) charmed mesons. Theoretical predictions from this mechanism are integrated over the experimental $v$ and $\overline{v}$ spectra, including a scaling background calculated from the parton model. This mechanism can approximately account for the high-$y$ $\overline{v}N$ data with an effective charm production threshold $W_{\mathrm{th}}=4\mathrm{}$ GeV and $F^{*}N$ total cross sections of order 10 mb. Better agreement is secured with a higher threshold $W_{\mathrm{th}}=6\mathrm{}$ GeV and higher charmed meson-nucleon cross sections. Unsuppressed weak current couplings to charmed $D^{*}$ mesons could enhance the vector-meson-dominance effect. The $v$ and $p$ distributions of the fast ${\mu }^{-}$ in the dimuon events are consistent with this $F^{*}$ vector-dominance contribution.

• Received 5 June 1975

DOI:https://doi.org/10.1103/PhysRevD.12.2628