The NEXT experiment for neutrinoless double beta decay searches

Neutrinoless double beta (0νββ) decay is a postulated radioactive process in which two neutrons inside a nucleus transform simultaneously into two protons emitting two electrons. Its discovery would demonstrate that neutrinos are Majorana particles and that total lepton number is not conserved in nature, findings with far-reaching implications in particle physics and cosmology. After seven decades of experimental effort, no compelling evidence for the existence of the decay has been obtained, but a new generation of experiments that are already running or about to run promises to push forward the current limits exploring the inverse-hierarchy region of neutrino masses.

In the seminar I will review the current status of the experimental searches for neutrinoless double beta decay, paying particular attention to the NEXT experiment, a high-pressure xenon gas TPC with electroluminescent amplification. Such a detector offers both high energy resolution and charged-particle tracking for the discrimination of signal and background. As I will discuss, the combination results in excellent experimental sensitivity to 0νββ decay.