# Flavor invariant and CPV

## Flavor invariant and CPV

Typically flavor is not invariant under symmetry. But if we want to construct the flavor invariant operators order by order, how should we do?

This is a quite different logic than constructing the effective operators. Flavor invariant using spurion fields.

• Hilbert Series for Leptonic Flavor Invariants in the Minimal Seesaw Model, arxiv

• Systematic construction of basis invariants in the 2HDM, arxiv

• Flavor Invariants and Renormalization-group Equations in the Leptonic Sector with Massive Majorana Neutrinos, arxiv

## EFT operator and flavor symmetry

One can impose the flavor symmetry, such as MFV for quark fields. In this case, Lagrangian has flavor symmetry.