Title: Search for Neutrinoless Double-Beta Decay

Speaker: Ibrahim Mirza, University of Tenessee, Knoxville

Abstract: Are neutrinos their own antiparticles? Search for an extremely rare and yet unobserved nuclear transition—neutrinoless double-beta decay (0νββ) decay if observed would prove neutrinos and antineutrinos are the same—Majorana neutrino. 0νββ decay violates lepton number conservation and could explain the origin of matter-antimatter asymmetry in the Universe. Neutrino oscillation proves neutrinos are massive, but the absolute neutrino masses are yet unknown. 0νββ decay would provide a model-dependent measurement of the absolute neutrino mass. The experimental search for 0νββ decay signal is extremely challenging since it requires a quasi-background-free experiment. The KamLAND-Zen experiment sets the most stringent lower limit on the half-life of 0νββ decay:T 0ν 1/2 > 3.8 ×1026 years, and corresponding upper limits on the absolute neutrino mass are in the range 28–122 meV. The new experiment LEGEND-200 started collecting data. Next-generation ton-scale experiments—LEGEND-1000, nEXO, SNO+, CUPID, KamLAND2-Zen etc are planned. In this talk, I will provide an introductory aspects of neutrinoless double-beta decay and an overview of different planned experiments, with a particular emphasis on the LEGEND-1000.