Present Status of Single Pion Production in Neutrino-Nucleus Reactions

TL;DR

This paper reviews recent theoretical progress in understanding single pion production in neutrino-nucleus reactions, highlighting data-model comparisons, the role of Watson's theorem, and the impact of new experimental results.

Contribution

It discusses the application of Watson's theorem to reconcile experimental data with theoretical models and compares recent MINERvA data with various theoretical approaches.

Findings

Watson's theorem helps reconcile ANL and BNL data.

Discrepancies between MiniBooNE data and models are analyzed.

MINERvA coherent pion production data are compared with models.

Abstract

Some of the recent progress in the physics of pion production induced by neutrinos on nucleons and nuclei is reviewed from a theoretical perspective. The importance of Watson's theorem to reconcile ANL and BNL data with the off-diagonal Goldberger-Treiman relation for the $\Delta(1232)$ is discussed. The disagreement between MiniBooNE data and theoretical calculations is presented in the light of the new MINERvA data. The coherent pion production data on $^{12}$C obtained by MINERvA are also compared to different microscopic and PCAC models.