Aspects of the Flavour Expansion Theorem

TL;DR

This paper revisits the Flavour Expansion Theorem, highlighting its advantages over traditional diagrammatic methods in flavor physics, especially in complex cases where standard techniques fall short.

Contribution

It provides a comprehensive review of the Flavour Expansion Theorem and compares its effectiveness with standard methods in flavor physics applications.

Findings

The theorem offers a more general algebraic approach.

It simplifies derivations in complex flavor scenarios.

It outperforms standard techniques when they become inadequate.

Abstract

The Flavour Expansion Theorem, which has been recently proposed as a more general and elegant algebraic method, for the derivation of the commonly used Mass Insertion Approximation, is revisited. The theorem is reviewed, with respect to its straightforward applications in Flavour physics, and compared against the standard diagrammatic flavour basis techniques, in cases where the latter become inadequate.