One-loop Matching for the Seesaw Model

TL;DR

This paper performs a comprehensive one-loop matching of the seesaw model to its low-energy effective theory, detailing the operators and threshold corrections essential for precise phenomenological studies.

Contribution

It provides the complete one-loop matching results, including 31 independent dimension-6 operators and threshold corrections, advancing the understanding of heavy neutrino effects at low energies.

Findings

31 independent dimension-6 operators identified

Threshold corrections to SM couplings calculated

Complete Lagrangian up to dim-6 derived

Abstract

In this talk, we present the results of the complete one-loop matching of the seesaw model onto its low-energy effective theory by integrating out three right-handed neutrinos at the one-loop level. We find that there are 31 independent dimension-6 (dim-6) operators (barring flavor structures and Hermitian conjugates) in the Warsaw basis, and the standard-model couplings and the Wilson coefficient of the Weinberg operator acquire threshold corrections at the one-loop level. The complete Lagrangian up to dim-6 at the one-loop level is derived, which is indispensable for consistent explorations of the impact of heavy right-handed neutrinos at low energies.