Minoo Kabirnezhad

I present a unified model for single pion production in photo-, electro-, and neutrino-nucleon interactions that is applicable across the broad kinematic range in the GeV regime relevant to accelerator-based neutrino experiments. The model incorporates vector and axial-vector transition form factors for excited nucleon states with masses up to 2 GeV, together with nonresonant background contributions, within a meson dominance framework that respects quantum chromodynamic constraints and preserves unitarity. This construction ensures the correct asymptotic behavior at large momentum transfer (𝑄2) while providing a consistent description of the resonance and transition regions. At very low 𝑄2, the implementation of the conserved vector current and partially conserved axial current relations leads to reliable predictions and helps address challenges encountered in current neutrino data analyses. The unified framework enables a global analysis that combines the available electron, photon, pion, and neutrino scattering data. This comprehensive approach allows detailed studies of nucleon structure in the resonance region and provides important constraints on weak interaction form factors, where modern neutrino-nucleon data remain limited. By determining all model parameters simultaneously with their correlated uncertainties, the approach establishes a robust, data-driven foundation for precision neutrino interaction modeling in support of next-generation neutrino oscillation measurements.