Parton model expectations for weak pion production by neutral currents

A quark model of the Weinberg-Salam theory is used in conjunction with the parton fragmentation hypothesis of Feynman to obtain the distribution of a final state hadron H produced in semi-inclusive neutrino reactions. A general relation is obtained between the neutral to charged current ratios R(H)= sigma ( nu to nu +H)/ sigma ( nu to mu /sup -/+H) and R(H)= sigma ( nu to nu +H)/ sigma ( nu to mu /sup +/+H) which is sensitive to the value of the parameter sin/sup 2/ theta . Particular relations are derived among the ratios R( pi ) and R( pi ). All predictions refer to the parton fragmentation region of phase space. Comparison is made with model independent bounds. (11 refs).