Quark-hadron duality and parity violating asymmetry of electroweak reactions in the Δ region -: art. no. 025204

A dynamical model [T. Sato and T.-S. H. Lee, Phys. Rev. C 54, 2660 (1996); 63, 055201 (2001); T. Sato, D. Uno, and T.-S. H. Lee, ibid. 67, 065201 (2003)] of electroweak pion production reactions in the Delta(1232) region has been extended to include the neutral current contributions for examining the local quark-hadron duality in neutrino-induced reactions and for investigating how the axial N-Delta form factor can be determined by the parity violating asymmetry of N(e(->),e(')) reactions. We first show that the recent data of (e,e(')) structure functions F-1 and F-2, which exhibit the quark-hadron duality, are in good agreement with our predictions. For possible future experimental tests, we then predict that the structure functions F-1,F-2, and F-3 for (nu,e) and (nu,nu(')) processes also show the similar quark-hadron duality. The spin-dependent structure functions g(1) and g(2) of (e,e(')) have also been calculated from our model. It is found that the local quark-hadron duality is not seen in the calculated g(1) and g(2), while our results for g(1) and some polarization observables associated with the exclusive p((e) over right arrow ,e(')pi) and (p) over right arrow((e) over right arrow ,e(')pi) reactions are in reasonably good agreement with the recent data. In the study of parity violating asymmetry A of N((e) over right arrow ,e(')) reactions, the relative importance between the nonresonant mechanisms and the Delta excitation is investigated by taking into account the unitarity condition. Predictions are made for using the data of A to test the axial N-Delta form factors determined previously in the studies of N(nu(mu),mu(-)pi) reactions. The predicted asymmetry A are also compared with the parton model predictions for future experimental investigations of quark-hadron duality.