Global fits of third family hypercharge models to neutral current B-anomalies and electroweak precision observables

Abstract

While it is known that third family hypercharge models can explain the neutral current B-anomalies, it was hitherto unclear whether the Z-Z′$$Z-Z^\prime $$ mixing predicted by such models could simultaneously fit electroweak precision observables. Here, we perform global fits of several third family hypercharge models to a combination of electroweak data and those data pertinent to the neutral current B-anomalies. While the Standard Model is in tension with this combined data set with a p-value of .0007, simple versions of the models (fitting two additional parameters each) provide much improved fits. The original Third Family Hypercharge Model, for example, has a p-value of .065$${.065}$$, with Δχ2=6.5σ$$\sqrt{\Delta \chi ^2}=6.5\sigma $$.