# Measurement of the single $\pi^0$ production rate in neutral current neutrino interactions on water

## TL;DR

This paper reports a measurement of the single neutral current $0$ production rate on water in a neutrino beam at 0.6 GeV, using subtraction techniques with the T2K near detector, and compares it to simulation predictions.

## Contribution

The study provides the first measurement of the neutral current single $0$ production rate on water at this energy, using water-in and water-out data for background subtraction.

## Key findings

- Measured rate is 0.68 times the predicted value.
- Results are consistent within uncertainties with the simulation.
- Provides data for neutrino interaction modeling at 0.6 GeV.

## Abstract

The single $\pi^0$ production rate in neutral current neutrino interactions on water in a neutrino beam with a peak neutrino energy of 0.6 GeV has been measured using the P{\O}D, one of the subdetectors of the T2K near detector. The production rate was measured for data taking periods when the P{\O}D contained water ($2.64\times{}10^{20}$ protons-on-target) and also periods without water ($3.49 \times 10^{20}$ protons-on-target). A measurement of the neutral current single $\pi^0$ production rate on water is made using appropriate subtraction of the production rate with water in from the rate with water out of the target region. The subtraction analysis yields 106 $\pm$ 41 (stat.) $\pm$ 69 (sys.) signal events, which is consistent with the prediction of 157 events from the nominal simulation. The measured to expected ratio is 0.68 $\pm$ 0.26 (stat.) $\pm$ 0.44 (sys.) $\pm$ 0.12 (flux). The nominal simulation uses a flux integrated cross section of $7.63\times{}10^{-39}$ cm${}^2$ per nucleon with an average neutrino interaction energy of 1.3 GeV.