EWPD constraints on flavor symmetric vector fields

Abstract

Electroweak precision data constraints on flavor symmetric vector fields are determined. The flavor multiplets of spin one that we examine are the complete set of fields that couple to quark bi-linears at tree level while not initially breaking the quark global flavor symmetry group. Flavor safe vector masses proximate to, and in some cases below, the electroweak symmetry breaking scale are found to be allowed. Many of these fields provide a flavor safe mechanism to explain the tt forward backward anomaly, and can simultaneously significantly raise the allowed values of the Standard Model Higgs mass consistent with electroweak precision data.

Bottom-Quark Forward-Backward Asymmetry in the Standard Model and Beyond

“…In models where the NP couples to quarks in a flavor universal way, the loop correction that gives the best-fit value for δg Rb will give an analogous correction to δg Ru,d , which is much larger than allowed by atomic parity violation experiments [50]. The tree level V − Z mixing of [62] is not a viable explanation either for the same reason. Axigluon models give δg Rb = δg Lb [50], which disagrees with the best-fit value for δg Lb , O(10 −3 ) [61].…”

“…The tree level V − Z mixing of [62] is not a viable explanation either for the same reason. Axigluon models give δg Rb = δg Lb [50], which disagrees with the best-fit value for δg Lb , O(10 −3 ) [61].…”

Particle Physics-Final Report

“…As a result FCNC's are consistent with experiment even for NP mass scales < TeV. With student Murphy and collaborator Trott, Grinstein studied further the constraints that electroweak precision tests impose on these models [105].…”

Top Quark FB Asymmetry And Flavor Physics

“…For additional constraints from LEP, electroweak precision measurements, LHC/Tevatron single top and dijet production, etc, see Refs. [31,32]. Neutral meson mixing gives the most severe constraints.…”