Proton decay and light sterile neutrinos

TL;DR

This paper explores how certain dimension-six operators involving light sterile neutrinos could lead to distinctive proton decay signatures, linking neutrino properties with proton stability in a new physics model.

Contribution

It identifies a novel proton decay mode involving a charged pion and missing energy as a signature of sterile neutrino related operators and presents a TeV-scale model connecting neutrino lightness and proton stability.

Findings

Charged pion plus missing energy decay mode as a signature

Effective operators involving sterile neutrinos can induce this decay

A concrete TeV-scale model links neutrino mass and proton stability

Abstract

Within the standard model, non-renormalizable operators at dimension six ($d=6$) violate baryon and lepton number by one unit and thus lead to proton decay. Here, we point out that the proton decay mode with a charged pion and missing energy can be a characteristic signature of $d=6$ operators containing a light sterile neutrino, if it is not accompanied by the standard $\pi^0e^+$ final state. We discuss this effect first at the level of effective operators and then provide a concrete model with new physics at the TeV scale, in which the lightness of the active neutrinos and the stability of the proton are related.