The NEXT experiment: A high pressure xenon gas TPC for neutrinoless double beta decay searches

TL;DR

The NEXT experiment aims to detect neutrinoless double beta decay using a high-pressure xenon gas TPC with electroluminescence readout, potentially revealing the Majorana nature of neutrinos and lepton number violation.

Contribution

It introduces a novel high-pressure xenon gas TPC with electroluminescence readout and SOFT technology for neutrinoless double beta decay searches.

Findings

Design of a large high-pressure xenon gas TPC with electroluminescence.

Implementation of SOFT technology for improved signal readout.

Preparation for data collection at LSC in 2014.

Abstract

Neutrinoless double beta decay is a hypothetical, very slow nuclear transition in which two neutrons undergo beta decay simultaneously and without the emission of neutrinos. The importance of this process goes beyond its intrinsic interest: an unambiguous observation would establish a Majorana nature for the neutrino and prove the violation of lepton number. NEXT is a new experiment to search for neutrinoless double beta decay using a radiopure high-pressure xenon gas TPC, filled with 100 kg of Xe enriched in Xe-136. NEXT will be the first large high-pressure gas TPC to use electroluminescence readout with SOFT (Separated, Optimized FuncTions) technology. The design consists in asymmetric TPC, with photomultipliers behind a transparent cathode and position-sensitive light pixels behind the anode. The experiment is approved to start data taking at the Laboratorio Subterr\'aneo de Canfranc (LSC), Spain, in 2014.