Selection of electron (anti-)neutrinos at the T2K near detector ND280

The intrinsic electron neutrino contamination of the T2K neutrino beam provides the single largest background in the measurement of electron neutrino appearance in T2K. These electron neutrinos can be measured directly in the T2K near detector ND280. Measurements of the intrinsic electron (anti-)neutrino backgrounds from the anti-neutrino running are shown, including details on the event selections and rejection of the large background of muons, photons, protons and pions. The ν_e and ${\bar{\nu }}_{e}$ beam compositions are then extracted and the rescaling parameters of the expected rate of ν_e and ${\bar{\nu }}_{e}$ events are f(ν_e) = 1.250 ± 0.135(stats.) ± 0.122(syst.) and $f({\bar{\nu }}_{e})=1.142\pm 0.144(stats.)\pm 0.132(syst.)$ respectively.