Implications of Rare Kaon Decays on Lepton Number Violating Interactions

TL;DR

This paper investigates how rare kaon decays could indicate lepton number violation, affecting neutrino mass models and high-scale leptogenesis, using a model-independent SMEFT approach and considering experimental prospects.

Contribution

It provides a model-independent analysis of lepton number violation in rare kaon decays and discusses implications for neutrino masses and leptogenesis.

Findings

Detection of LNV in kaon decays would challenge high-scale leptogenesis.

LNV interactions in kaon decays suggest small radiative neutrino masses.

Analysis aligns with current NA62 experimental capabilities.

Abstract

We explore the possibility of lepton number violation (LNV) manifesting in the rare kaon decay $K\to\pi\nu\nu$, and its consequences for radiative neutrino mass generation and the washout of Lepton asymmetry in high-scale leptogenesis scenarios. We perform the analysis in a model-independent framework, the Standard Model effective field theory (SMEFT), and discuss the possible LNV nature of the rare kaon decay in the context of the currently operating NA62 experiment at CERN. We find that, in case of a LNV interaction, its detection would put high-scale leptogenesis under tension and would hint to small radiatively generated neutrino masses.