Search for lepton-number-violating neutrinoless double beta decay with LEGEND: First year of LEGEND-200 physics data

Pin-Jung Chiu^1*

¹Department of Physics, National Taiwan University, Taipei, Taiwan

* Presenter:Pin-Jung Chiu, email:pin-jung.chiu@phys.ntu.edu.tw

The nature of neutrinos remains a long-standing question in modern physics. The observation of a hypothesized, extremely rare process, neutrinoless double beta decay (0νββ), would demonstrate that neutrinos have a Majorana mass and would establish lepton-number violation. In this presentation, I will introduce the LEGEND experiment, a two-phased project searching for 0νββ in ⁷⁶Ge. I will show the latest results from the first physics run of the Phase I experiment, accumulated with 61 kg yr of exposure, and discuss the ongoing R&D projects contributing to the goal of the Phase II experiment to improve the discovery sensitivity by an additional order of magnitude, eventually probing the entire inverted-neutrino-mass-ordering regime.

Keywords: Neutrino, Double beta decay , Lepton number violation , Majorana nature , High-purity germanium detector