Predicting ${\cal{B}}(B\to K^{(*)}\nu \bar \nu)$ within the MFV-SMEFT using $B$, Top, $Z$ and Drell-Yan data

Abstract

In high-energy physics, the Standard Model Effective Field Theory (SMEFT) serves as a framework for investigating new physics phenomena without relying on a specific model. In this study, we assess the potential of combining observables from different physics sectors in a unified SMEFT fit. Our analysis considers top-quark measurements, 𝑏 → 𝑠 flavor changing neutral current transitions, transitions like 𝑍 → 𝑏 b and 𝑍 → 𝑐 c, alongside Drell-Yan data from the Large Hadron Collider (LHC). We explore the influence of Minimal Flavor Violation (MFV) when used as a flavor pattern in the global fit. By incorporating observables from different physics sectors, we can address flat directions in the parameter space and draw conclusions about the flavor structure based on the MFV parameterization. We demonstrate that the combination of measurements from different sectors yields stronger constraints on the SMEFT coefficients than the individual fits and emphasize how synergies in the global approach allow probing scales as high as 18 TeV. Based on the constraints on the Wilson coefficients obtained in our analysis, we predict 𝑏 → 𝑠𝜈 ν branching ratios and and discuss how future measurements of these observables could provide new information in the search for physics beyond the Standard Model when being included in the global fit.