Measurements of the $\nu_{\mu}$ and $\bar{\nu}_{\mu}$-induced Coherent Charged Pion Production Cross Sections on $^{12}C$ by the T2K experiment

TL;DR

This paper presents the first measurement of antineutrino-induced coherent charged pion production cross section on carbon, updating previous muon neutrino results, and compares findings with theoretical models at around 0.85 GeV.

Contribution

It provides the first measurement of antineutrino coherent pion production cross section on carbon and updates muon neutrino measurements within the T2K experiment.

Findings

Muon neutrino cross section: (2.98 ± 0.37 (stat.) ± 0.31 (syst.)) × 10^{-40} cm^2

Antineutrino cross section: (3.05 ± 0.71 (stat.) ± 0.39 (syst.)) × 10^{-40} cm^2

Results agree with NEUT and GENIE model predictions.

Abstract

We report an updated measurement of the $\nu_{\mu}$-induced, and the first measurement of the $\bar{\nu}_{\mu}$-induced coherent charged pion production cross section on $^{12}C$ nuclei in the T2K experiment. This is measured in a restricted region of the final-state phase space for which $p_{\mu,\pi} > 0.2$ GeV, $\cos(\theta_{\mu}) > 0.8$ and $\cos(\theta_{\pi}) > 0.6$, and at a mean (anti)neutrino energy of 0.85 GeV using the T2K near detector. The measured $\nu_{\mu}$ CC coherent pion production flux-averaged cross section on $^{12}C$ is $(2.98 \pm 0.37 (stat.) \pm 0.31 (syst.) \substack{ +0.49 \\ -0.00 } \mathrm{ (Q^2\,model)}) \times 10^{-40}~\mathrm{cm}^{2}$. The new measurement of the $\bar{\nu}_{\mu}$-induced cross section on $^{12}{C}$ is $(3.05 \pm 0.71 (stat.) \pm 0.39 (syst.) \substack{ +0.74 \\ -0.00 } \mathrm{(Q^2\,model)}) \times 10^{-40}~\mathrm{cm}^{2}$. The results are compatible with both the NEUT 5.4.0 Berger-Sehgal (2009) and GENIE 2.8.0 Rein-Sehgal (2007) model predictions.