PCAC and coherent pion production by low energy neutrinos

TL;DR

This paper analyzes coherent pion production by low energy neutrinos using PCAC theory, emphasizing lepton mass effects and utilizing pion-carbon scattering data, with results aligning with some experimental limits but differing from recent findings.

Contribution

It applies PCAC theory to low energy neutrino-induced pion production, incorporating pion-nucleus scattering data instead of models, and highlights lepton mass effects on production suppression.

Findings

Results agree with existing upper limits for pi^+ production.

Predictions are below recent MiniBooNE pi^0 production results.

Lepton mass effects significantly suppress pi^+ production.

Abstract

Coherent pi^+ and pi^0 production in low energy neutrino reactions is discussed in the framework of the partially conserved axial vector current theory (PCAC). The role of lepton mass effects in suppressing the pi^+ production is emphasized. Instead of using models of pion nucleus scattering, the available data on pion Carbon scattering are implemented for an analysis of the PCAC prediction. Our results agree well with the published upper limits for pi^+ production but are much below the recent MiniBooNE result for pi^0 production.