Search for Nucleon Decays With EXO-200

Abstract

A search for instability of nucleons bound in ¹³⁶Xe nuclei is reported with 223 kg·yr exposure of ¹³⁶Xe in the EXO-200 experiment. Lifetime limits of 3.3 x 10²³ and 1.9 x 10²³ yr are established for nucleon decay to ¹³³Sb and ¹³³Te, respectively. These are the most stringent to date, exceeding the prior decay limits by a factor of 9 and 7, respectively.