# Effective Theories for Quark Flavour Physics

## TL;DR

This paper reviews how effective field theories are used to analyze quark flavor processes, enabling the probing of New Physics through meson mixing and CP violation measurements.

## Contribution

It provides a comprehensive overview of effective Hamiltonians for quark decays and mixing, highlighting their role in constraining New Physics beyond the Standard Model.

## Key findings

- Effective Hamiltonians describe quark weak decays and meson mixing.
- Constraints on New Physics are derived from $ riangle F=2$ processes.
- Unitarity Triangle analysis tightens bounds on beyond Standard Model theories.

## Abstract

The purpose of these lectures is to provide the reader with an idea of how we can probe New Physics with quark flavour observables using effective theory techniques. After giving a concise review of the quark flavour structure of the Standard Model, we introduce the effective Hamiltonian for quark weak decays. We then consider the effective Hamiltonian for $\Delta F=2$ transitions in the Standard Model and beyond. We discuss how meson-antimeson mixing and CP violation can be described in terms of the $\Delta F=1$ and $\Delta F=2$ effective Hamiltonians. Finally we present the Unitarity Triangle Analysis and discuss how very stringent constraints on New Physics can be obtained from $\Delta F=2$ processes.