Topological signature in the NEXT high pressure xenon TPC

Abstract

The NEXT experiment aims to observe the neutrinoless double beta decay of Xe-136 in a high-pressure xenon gas TPC using electroluminescence to amplify the signal from ionization. One of the main advantages of this technology is the possibility to use the topology of events with energies close to Qbb as an extra tool to reject background. In these proceedings we show with data from prototypes that an extra background rejection factor of 24.3 +- 1.4 (stat.)% can be achieved, while maintaining an efficiency of 66.7 +- 1.% for signal events. The performance expected in NEW, the next stage of the experiment, is to improve to 12.9% +- 0.6% background acceptance for 66.9% +- 0.6% signal efficiency.