Fermion mixing in quasi-free states

TL;DR

This paper extends fermion oscillation formulas beyond traditional Fock space to include general quasi-free states and non-unitary mixing, broadening the theoretical framework for fermion mixing.

Contribution

It introduces a generalized approach to fermion oscillations that encompasses quasi-free states and non-unitary mixing, expanding the scope of quantum field theoretic models.

Findings

Extended oscillation formulas to quasi-free states

Included non-unitary mixing cases

Broadened theoretical understanding of fermion oscillations

Abstract

Quantum field theoretic treatments of fermion oscillations are typically restricted to calculations in Fock space. In this letter we extend the oscillation formulae to include more general quasi-free states, and also consider the case when the mixing is not unitary.