A nonlocal theory of fermion mixing

TL;DR

This paper introduces a nonlocal approach to fermion mixing, deriving a transition probability formula that generalizes local theories and exploring phenomenological implications with string-inspired models.

Contribution

It presents a novel nonlocal formalism for fermion mixing, incorporating delocalized mixing terms and perturbative interactions, extending the traditional local oscillation framework.

Findings

Derived a nonlocal oscillation formula consistent with local limits

Applied the formalism to string-inspired kernels showing phenomenological deviations

Demonstrated the approach's potential to modify standard fermion mixing predictions

Abstract

We study a nonlocal generalization of two flavor fermion mixing and compute the transition probability by means of the path integral formalism. In our treatment, we delocalize only the mixing term, and consider a perturbative interaction with a small mixing angle. The oscillation formula derived reduces to the correct local form when the appropriate limit is considered. We apply our formalism to some string-inspired delocalization kernels and discuss the phenomenological deviations from the local theory.