Studies of Non-standard Particle Mixings Through Singular Values

Abstract

Singular values provide a method to study mixing matrices in particle physics. The methods of unitary dilations and the cosine-sine matrix decomposition are discussed in the framework of the Standard Model neutrinos mixing with one non-standard neutrino. We show that the mixings are continuous functions of singular values. It implies that the magnitude of non-standard mixing can be estimated from below and above unambiguously from the experimentally determined interval PMNS mixing matrix.