Search for short baseline ${\nu }_e$ disappearance with the T2K near detector

The T2K experiment has performed a search for ${\nu }_e$ disappearance due to sterile neutrinos using $5.9\times {10}^{20}$ protons on target for a baseline of $280m$ in a neutrino beam peaked at about $500MeV$. A sample of \nu_e CC interactions in the off-axis near detector has been selected with a purity of 63% and an efficiency of 26%. The p-value for the null hypothesis is 0.085 and the excluded region at 95% CL is approximately $si{n}^{2}2{\theta }_{ee}>0.3$ for $\mathrm{\Delta }{m}_{eff}^2>7e{V}^2\mathrm{/}{c}^4$.