$$M_W$$ helps select $$Z^\prime $$ models for $$b\rightarrow s \ell \ell $$ anomalies

Abstract

AbstractAs shown in Allanach et al. (Global fits of third family hypercharge models to neutral current B-anomalies and electroweak precision observables. arXiv:2103.12056), the Third Family Hypercharge ($$Y_3$$ Y 3 ) Model changes the Standard Model prediction for $$M_W$$ M W whilst simultaneously explaining anomalies in $$b\rightarrow s\ell \ell $$ b → s ℓ ℓ transitions via a heavy $$Z^\prime $$ Z ′ gauge boson which is spawned by a spontaneously broken gauged $$U(1)_{Y_3}$$ U ( 1 ) Y 3 symmetry. The 2022 CDF II measurement of $$M_W$$ M W , which is far from the Standard Model prediction in the statistical sense, somewhat disfavours the $$Y_3$$ Y 3 model. Here, we generalise the gauge charge assignments to the anomaly-free combination $$s Y_3 + t (B_3-L_3)$$ s Y 3 + t ( B 3 - L 3 ) and show that incorporating the 2022 CDF II measurement of $$M_W$$ M W selects a viable domain of integers s and t. For example, $$s=1, t=-3$$ s = 1 , t = - 3 yields a p value of .08 in a two-parameter global fit to 277 electroweak and flavour changing b data, much improving a SM p value of $$1\times 10^{-6}$$ 1 × 10 - 6 .