Search for coherent charged pion production in neutrino-carbon interactions

TL;DR

This paper reports a search for charged-current coherent pion production in neutrino-carbon interactions at around 1.3 GeV, finding no evidence and setting the first experimental upper limit on the process in this energy range.

Contribution

It provides the first experimental upper limit on coherent charged pion production in neutrino interactions at a few GeV energy.

Findings

No evidence for coherent pion production was observed.

An upper limit of 0.006 on the cross section ratio was set.

First experimental constraint in this energy region.

Abstract

We report the result from a search for charged-current coherent pion production induced by muon neutrinos with a mean energy of 1.3 GeV. The data are collected with a fully active scintillator detector in the K2K long-baseline neutrino oscillation experiment. No evidence for coherent pion production is observed and an upper limit of $0.60 \times 10^{-2}$ is set on the cross section ratio of coherent pion production to the total charged-current interaction at 90% confidence level. This is the first experimental limit for coherent charged pion production in the energy region of a few GeV.