# Spin asymmetry in single pion production induced by weak interactions of neutrinos with polarized nucleons

## TL;DR

This paper investigates how spin asymmetries in single pion production by neutrinos on polarized nucleons can reveal details about the underlying interaction dynamics, especially the interference between resonance and nonresonance processes.

## Contribution

It introduces predictions for spin asymmetries in neutrino-induced single pion production considering different target polarizations, highlighting their sensitivity to the nonresonance background.

## Key findings

- Spin asymmetry provides complementary information to spin-averaged cross sections.
- Normal polarization asymmetry is sensitive to interference between resonance and nonresonance contributions.
- The approach enhances understanding of SPP dynamics and background modeling.

## Abstract

The single pion production (SPP) in the charged-current neutrino (antineutrino) scattering off the polarized nucleon is discussed. The spin asymmetry is predicted within two approaches. The spin polarizations of the target nucleon that are longitudinal and perpendicular to the neutrino momentum are considered. It is shown, in several examples, that information about the SPP dynamics coming from the spin asymmetry is complementary to information obtained from measurements of spin averaged cross section. Indeed, the spin asymmetry is sensitive to the nonresonance background description of the SPP model. For the normal polarization of the target, the spin asymmetry is given by the interference between the resonance and the nonresonance contributions.