  We have applied a microscopic model for single photon emission in neutral
current interactions on nucleons and nuclei to determine the number and
distributions of such events at the Super-Kamiokande detector, for the flux and
beam exposure of the T2K experiment in neutrino mode. These reactions represent
an irreducible background in electron-(anti)neutrino appearance measurements
aimed at a precise measurement of mixing angle $\theta_{13}$ and the $CP$
violating phase. We have obtained a total number of photon events that is twice
larger than the one from the NEUT event generator (version 5.1.4.2) used in the
analysis of T2K data. Detailed comparisons of energy and angular distributions
for the $\nu_\mu$ and $\bar\nu_\mu$ fluxes have also been performed.
