Description:

Title: An effective field theory approach to neutrinoless double beta deca

Speaker: Emanuele Mereghetti, Los Alamos National Laboratory
 

Abstract: Neutrinoless double-beta decay experiments probe the nature of neutrino masses and the conservation of lepton number.
A discovery in the next generation of experiments will have profound implications: it will demonstrate that neutrinos are Majorana fermions, shed light on the mechanism of neutrino mass generation, and give insight on leptogenesis scenarios for the generation of the matter-antimatter asymmetry in the universe. By itself, however, the observation of neutrinoless double-beta decay will not immediately point to the underlying physical origin of lepton number violation (LNV). In this talk I will discuss LNV in the framework of effective field theories. After introducing LNV interactions at the electroweak scale, I will discuss their possible manifestations at colliders. I will then match these interactions onto LNV operators at low-energy, going beyond a neutrino Majorana mass. I will derive the operators that mediate double-beta decay in chiral effective theory, for light Majorana neutrino exchange and higher-dimensional LNV operators, discuss the existing constraints on LNV interactions, and the implications for the interpretation of a signal (or lack of thereof) in the next generation of double-beta experiments.

Keywords: Physics, Astronomy, HEP