A Search for Neutral Current Single Gamma with ND280 at T2K

Abstract

The methodology and preliminary results for the search of single photons initiated by Neutral Current neutrino interactions with the ND280 detector at the T2K experiment are presented. This measurement aims to set the first limit on single-photon neutrino production below 1~GeV. Neutrino production of single photon is a subdominant process in neutrino interactions. Because photons and electrons have very similar signatures in neutrino detectors, careful estimations need to be made not to bias the \nue appearance oscillation results of accelerator neutrino experiments. The single photons are created by a nuclear resonance (typically $\Delta$(1232)) after interaction of the neutrino. The cross section is expected to be of the order of $10^{-42} cm^{2}$. The main background is composed of $\pi^{0}$ decaying into two photons, where only one photon is detected, and $\pi^{0}$ events creating photons from outside of the fiducial volume.