Non-unitarity of the leptonic mixing matrix in the TeV-scale type-I seesaw model

TL;DR

This paper investigates the non-unitarity effects in leptonic flavor mixing within the TeV-scale type-I seesaw model, revealing correlations among parameters and limitations on their phenomenological significance.

Contribution

It provides an analytical and numerical analysis of non-unitarity parameters, showing their dependence on model parameters and constraining their phenomenological impact.

Findings

All six non-unitarity parameters relate to three model parameters.

Correlations among non-unitarity parameters are derived.

Certain parameters ta_{e} and ta_{} are not phenomenologically significant.

Abstract

The non-unitarity effects in the leptonic flavor mixing are regarded as one of the generic features of the type-I seesaw model. Therefore, we explore these effects in the TeV-scale type-I seesaw model, and show that there exist non-trivial correlations among the non-unitarity parameters, stemming from the typical flavor structure of the low-scale seesaw model. In general, it follows from analytical discussions and numerical results that all the six non-unitarity parameters are related to three model parameters, while the widely studied parameters \eta_{e\tau} and \eta_{\mu\tau} cannot be phenomenologically significant