Quark-Parton Model Predictions for Hadronic Charge Ratios in Inclusive Lepton-Induced Reactions

We investigate the predictions of the quark-parton model for hadronic charge ratios in the current-fragmentation region in inclusive lepton-induced reactions. We use parton distribution functions given by McElhaney and Tuan from fits to single-arm inelastic electron scattering data, and we obtain relative parton fragmentation functions from a fit to the $\frac{{\pi }^{+}}{{\pi }^{-}}$ ratio in electroproduction from a proton target. The electroproduced $\frac{{\pi }^{+}}{{\pi }^{-}}$ ratio from a neutron target is predicted to be ≳ 1.2 at moderate $\omega$ and $\omega$, providing a dramatic test of the model. The model gives a neutrino-(antineutrino-) produced $\frac{{\pi }^{+}}{{\pi }^{-}}$ ($\frac{{\pi }^{-}}{{\pi }^{+}}$) ratio of 3.0 ± 0.6 from any target. Also the ratio of charged to neutral $K$ production in $e^{+}{e}^{-}$ annihilation should be 1.38 ± 0.10.