Resonance-background interference in c.c. neutrino-induced π+ production

The recently observed anomalies and asymmetries in the angular distribution of the c.c. neutrino-induced π+ production are analyzed in the framework of a model of the π+ production mechanism which allows for the effects of resonance-background interference: it is found that their interpretation can be reasonably justified in terms of these effects. A particular relevance is given to the momentum-transfer dependence of the parameters characterizing the angular distribution (δ++ decay matrix elements, ''illegal moments'' and so on), with a comparison with the available data in different ranges of the neutrino energy. A satisfying agreement between theoretical predictions and experimental data is obtained. (author)