Flavor changing interactions confronted with meson mixing and hadron colliders

TL;DR

This paper examines how flavor-changing interactions mediated by new vector bosons impact meson mixing, deriving bounds from meson data that challenge some recent new physics explanations for flavor anomalies.

Contribution

It provides updated lower mass bounds on vector mediators from meson mixing data and compares these constraints with collider bounds, highlighting the greater sensitivity of meson systems.

Findings

Meson mixing data impose stronger bounds on vector mediators than colliders.

Recent new physics explanations for flavor anomalies are disfavored by these bounds.

Meson systems can significantly constrain beyond Standard Model theories.

Abstract

We have witnessed some flavor anomalies appeared in the past years, and explanations based on extended gauge sectors are among the most popular solutions. These beyond the Standard Model (SM) theories often assume flavor changing interactions mediated by new vector bosons, but at the same time they could yield deviations from the SM in the $K^{0}-\bar{K}^{0}$, $D^{0}-\bar{D}^{0}$, $B^0_d-\bar{B^0}_d$ and $B^0_s-\bar{B^0}_s$ meson systems. Using up-to-date data on the mass difference of these meson systems, we derive lower mass bounds on vector mediators for two different parametrizations of the quark mixing matrices. Focusing on a well-motivated model, based on the fundamental representation of the weak SU(3) gauge group, we put our findings into perspective with current and future hadron colliders to conclude that meson mass systems can give rise to bounds much more stringent than those from high-energy colliders and that recent new physics interpretations of the $b\rightarrow s$ and $R(D^{\ast})$ anomalies are disfavored.