Evaluating The Two Loop Diagram Responsible For Neutrino Mass In Babu's Model

TL;DR

This paper provides an exact calculation of the two-loop integral responsible for neutrino mass generation in Babu's model, clarifying the mass matrix structure and its implications.

Contribution

The paper presents the first exact evaluation of the two-loop integral in Babu's neutrino mass model, improving understanding of the mass matrix.

Findings

Exact two-loop integral calculated

Neutrino mass matrix structure clarified

Implications for neutrino mass spectrum analyzed

Abstract

Babu studied the neutrino spectrum obtained when one adds a charged singlet and a doubly charged singlet to the standard model particle spectrum. It was found that the neutrinos acquire a mass matrix at the two-loop level which contains one massless eigenstate. The mass matrix of Babu's model depends on an integral over the undetermined loop momenta. We present the exact calculation of this integral.