Electroweak Form Factors of the $\Delta$(1232) Resonance

Abstract

Nucleon $\to \Delta (1232)$ transition electroweak form factors are discussed in a single pion production model with nonresonant background terms originating from a chiral perturbation theory. Fits to electron-proton scattering $F_2$ as well as neutrino scattering bubble chamber experimental data are performed. Both $\nu$-proton and $\nu$-neutron channel data are discussed in a unified statistical model. A new parametrization of the $N\to \Delta (1232)$ vector form factors is proposed. Fit to neutrino scattering data gives axial mass $M_{A\Delta }=0.85+0.09-0.08$(GeV) and $C_5^A(0)=1.10+0.15-0.14$ in accordance with Goldberger-Treiman relation as long as deuteron nuclear effects are considered.

Comments: 11 pages, 8 figures