Isospin-½ nucleon-resonance production by aV,Aweak neutral current

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A set of ratios characterizing the production of the isospin-1/2 resonances D$sub 13$(1514) and S$sub 11$(1505), as well as the isospin-3/2 resonance P$sub 33$(1232), by electromagnetic and weak (charged and neutral) currents are defined. Assuming the most general weak neutral current with V, A spatial structure, the matrix elements needed to extract the production ratios are calculated in three dynamical models for resonance production: the Born- approximation model, the nonrelativistic quark model, and the quark-bag model. For the special case of the Weinberg-Salam theory neutral current, the three models suggest that for 0 < or = sin$sup 2$theta/subW/ < or = 0.5 the ratios D$sub 13$/P$sub 33$ and S$sub 11$/P$sub 33$ observed in neutral-current $pi$$sup 0$ or eta production on a free nucleon target should be substantially smaller (by a factor of 2 to 4) than the corresponding ratios observed in charged-current $pi$$sup 0$ or eta production. An attempt is made to predict the ratios D$sub 13$/P$sub 33$ and S$sub 11$/P$sub 33$ to be expected in charged-current production from the corresponding ratios observed in electroproduction, but here the three models do not agree, and so it is possible only to state a wide possible range in which the values of the ratios may lie. The charge-exchange corrections needed for comparison with experiments on complex nuclear targets are briefly discussed; it is found that for an aluminum target the reduction factors quoted above are halved, so that in neutral-current-induced reactions the ratios D$sub 13$/P$sub 33$ and S$sub 11$/P$sub 33$ are smaller by a factor of 1 to 2 than the corresponding ratios observed in charged-current--induced reactions. (AIP)