New Physics in CP Violating and Flavour Changing Quark Dipole Transitions

TL;DR

This paper investigates how heavy new physics could cause CP violation and flavour-changing effects in quark dipole transitions, using SMEFT, RG evolution, and experimental bounds to connect high-scale theories with low-energy observables.

Contribution

It establishes the relevant dimension six operators, analyzes RG-induced correlations, and sets bounds on Wilson coefficients at high scales within specific flavour models.

Findings

Bounds on Wilson coefficients at 5 TeV scale

Identification of most sensitive CPV observables

Connections between high-scale NP and low-energy CPV effects

Abstract

We explore CP-violating (CPV) effects of heavy New Physics in flavour-changing quark dipole transitions, within the framework of Standard Model Effective Field Theory (SMEFT). First, we establish the relevant dimension six operators and consider the Renormalisation Group (RG) evolution of the appropriate Wilson coefficients. We investigate RG-induced correlations between different flavour-violating processes and electric dipole moments (EDMs) within the Minimal Flavour Violating and $U(2)^3$ quark flavour models. At low energies, we set bounds on the Wilson coefficients of the dipole operators using CPV induced contributions to observables in non-leptonic and radiative $B$, $D$ and $K$ decays as well as the neutron and electron EDMs. This enables us to connect observable CPV effects at low energies and general NP appearing at high scales. We present bounds on the Wilson coefficients of the relevant SMEFT operators at the high scale $\Lambda = 5~{\rm TeV}$, and discuss most sensitive CPV observables for future experimental searches.