B Flavor Anomalies: 2021 Theoretical Status Report

At the present time (2022), there are discrepancies with the predictions of the Standard Model in several observables involving b -> sl(+)l(-) and b -> cl(-)(v) over bar (l) decays. These are the B flavor anomalies. In this review, we summarize the data as of Moriond 2021 and present theoretical new physics explanations from both a model-independent effective field theory point of view and through the building of explicit models. Throughout, we stress the complementarity of these two approaches. In addition, we discuss combined explanations of both B anomalies and present models that also explain other problems, such as dark matter, (g - 2)(mu), neutrino properties, and hadronic anomalies.

Automated summary

This review summarizes the observational data and theoretical explanations of the B flavor anomalies. The authors discuss both model-independent effective field theory approaches and explicit model building methods, emphasizing the complementarity between the two. In addition, combined explanations for the B anomalies and other related problems are presented.