Charged-particle multiplicity distributions inνnandνpcharged-current interactions

Charged-hadron multiplicity distributions in $\nu n$ and $\nu p$ interactions are measured in an exposure of the Fermilab deuterium-filled 15-foot bubble chamber to a wide-band neutrino beam. Multiplicity moments are studied as functions of the invariant mass of the hadronic system $W$ in the range $1<W<\mathrm{}15\mathrm{}$ GeV. The mean multiplicities for both $\nu n$ and $\nu p$ are found to increase logarithmically with $W^2$ with identical slopes but slightly different intercepts. A linear rise of the dispersion $D$ with the mean multiplicity $〈n_{\mathrm{ch}}〉$ is observed with an approximate slope of 0.35. This value is similar to that found in $e^{+}{e}^{-}$ and $\overline{p}p$ annihilation and is much less than the asymptotic prediction of QCD. A close similarity between $D_{-}$ vs $〈n_{-}〉$ in $\nu n$ and $\nu p$ interactions is seen. Negative correlations between the multiplicity distributions in the forward and backward hadronic center-of-mass hemispheres are found and discussed.