Top forward-backward asymmetry and the CDF Wjj excess in leptophobic U(1)' flavor models

TL;DR

This paper develops anomaly-free leptophobic U(1)' models with a light Z' boson to explain the top forward-backward asymmetry and Wjj excess observed at CDF, incorporating new Higgs doublets and scalar contributions.

Contribution

It introduces a novel class of anomaly-free leptophobic U(1)' flavor models with light Z' and additional Higgs doublets, explaining specific collider anomalies.

Findings

Models can accommodate the top FB asymmetry and Wjj excess.

Scalar and Z' contributions help evade constraints from same sign top pair production.

Predicted asymmetry and cross sections are consistent with experimental observations.

Abstract

We construct anomaly-free leptophobic U(1)' flavor models with light Z'(~ 145 GeV). In order to allow renormalizable Yukawa interactions for the standard model chiral fermions, new Higgs doublets with nonzero U(1)' charges are introduced. Then the neutral (pseudo)scalar Higgs bosons as well as Z' contribute to the t\bar{t} and the same sign top pair productions [\sigma(t\bar{t}]) and \sigma(tt)], and one can evade the strong constraint from \sigma(tt). The top forward-backward asymmetry (A_{FB}) and Wjj excess at CDF could be accommodated by A_{FB}^{New} = 0.084 ~ 0.12 and \sigma(W j j) \lesssim O(10) pb \times \sin^2 2 \beta.