Search for short baseline $\nu_e$ disappearance with the T2K near detector

TL;DR

This paper reports a search for short baseline electron neutrino disappearance using the T2K near detector, setting limits on sterile neutrino parameters with a specific dataset and analysis method.

Contribution

It presents the first search for $ u_e$ disappearance at short baseline with the T2K near detector, providing new constraints on sterile neutrino models.

Findings

Null hypothesis p-value = 0.085

Excluded region: $sin^2 2 heta_{ee} > 0.3$ for $ riangle m^2_{eff} > 7 eV^2/c^4$

Set new limits on sterile neutrino mixing parameters.

Abstract

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 $280 m$ in a neutrino beam peaked at about $500 MeV$. 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 $sin^2 2 \theta_{ee} > 0.3$ for $\Delta m^2_{eff} > 7 eV^2 / c^4$.