Status and Prospects for the EXO-200 and nEXO Experiments

Abstract

Large ultra-low background liquid xenon detectors have recently emerged as a promising technology that can push the neutrinoless double beta decay search to unprecedented sensitivity. Since it began operation, EXO-200 has completed one of the most sensitive searches for 0νββ decay of 136Xe using its first two years of data. After an unexpected interruption, due to underground incidents at the Waste Isolation Pilot Plant (WIPP), EXO-200 has started its Phase-II running in April 2016 with upgrades to its front-end electronics and Rn suppression system. In this article, we report the performance data of upgraded EXO-200 detector and the projected sensitivity for its Phase-II running. nEXO is a next-generation tonne-scale experiment building on the success of EXO-200. This 5 tonne LXe detector will be capable of probing Majorana neutrino mass in the inverted mass hierarchy region. The status of the nEXO experiment will be discussed in the article.