Weak Production of Nucleon Resonances
Abstract
We present a dynamical and fully covariant model for the weak production from nucleons of the N^{*}(1236) and highermass resonances. The analytic structure and unitarity of the partialwave helicity amplitudes are incorporated in this model which has a simple ND form. Above the ππN threshold, the excitation and rescattering of hadronic eigenstates are considered. For the excitation mechanism we use pion, nucleon, and vectormeson exchange. By using the conserved vectorcurrent theory and a previous calculation for electroproduction, we ascertain beforehand all the necessary normalizations, which result from the finalstate enhancement factors, and thereby perform an absolute calculation for weak production. Predictions are given for the differential and total cross sections in the first four resonance regions, and a favorable comparison is made with the existing data from CERN. Our results for the N^{*}(1236) are considerably different from the predictions made by Adler in a calculation which treats that one resonance. Since we derive the crosssection formulas keeping all dependence on the lepton mass, we can examine the interesting behavior as the forward direction is approached. The partially conserved axialvector current hypothesis, its implications for resonance production, and the role of our model in designing a test of it are also discussed.
 Publication:

Physical Review D
 Pub Date:
 December 1971
 DOI:
 10.1103/PhysRevD.4.3350
 Bibcode:
 1971PhRvD...4.3350Z