Explaining the $R_{K^{(*)}}$ anomalies and the CDF $M_W$ in Flavorful Top Seesaw Models with Gauged $U(1)_{L(-R)}$

Abstract

A new heavy Z vector boson provides a possible explanation for the neutral current B anomalies and points to the scale where we expect the solution to the hierarchy problem to appear. In this paper, we explore a modified Top Seesaw model based on the global symmetry breaking of U (3) L to U (2) L . The symmetry is partially gauged such that the breaking introduces not only a composite Higgs doublet but also a TeV-scale Z boson. The U (3) L /U (2) L Top Seesaw model predicts a light Higgs boson as well as a large top Yukawa coupling. Additional U (1) symmetry is gauged such that a flavorful TeV-scale Z boson is introduced to address the B anomalies. The existence of a heavy vector-like top quark and Z − Z mixing breaks the custodial symmetry, which predicts a heavier W mass as observed by the CDF collaboration. Two possible candidates for the U (1) symmetry corresponding to the Z boson, U (1) L and U (1) L−R , are discussed in detail. The parameter space for the models to address both anomalies is presented. The direct searches of the Z boson from dilepton channels are also studied. Based on the assumptions, a TeV-scale Z boson is still viable and can be probed in the near future.