Color & Weak triplet scalars, the dimuon asymmetry in $B_s$ decay, the top forward-backward asymmetry, and the CDF dijet excess

TL;DR

This paper proposes a model with color and weak triplet scalars that can simultaneously explain several anomalies in particle physics experiments, while remaining consistent with flavor and electroweak constraints.

Contribution

The authors introduce a flavor-symmetric scalar triplet model based on gauge invariance that can address multiple experimental anomalies in a unified framework.

Findings

The model can explain the top FBA and dimuon asymmetry or the dijet excess, but not all three simultaneously.

It predicts a pattern of flavor violation with $h_d \\ll h_s$ in relevant parameter regions.

The model favors a Higgs mass above the LEP bound and predicts significant effects on Higgs production and decay.

Abstract

The new physics required to explain the anomalies recently reported by the D0 and CDF collaborations, namely the top forward-backward asymmetry (FBA), the like-sign dimuon charge asymmetry in semileptonic b decay, and the CDF dijet excess, has to feature an amount of flavor symmetry in order to satisfy the severe constrains arising from flavor violation. In this paper we show that, once baryon number conservation is imposed, color & weak triplet scalars with hypercharge $Y=1/3$ can feature the required flavor structure as a consequence of standard model gauge invariance. The color & weak triplet model can simultaneously explain the top FBA and the dimuon charge asymmetry or the dimuon charge asymmetry and the CDF dijet excess. However, the CDF dijet excess appears to be incompatible with the top FBA in the minimal framework. Our model for the dimuon asymmetry predicts the observed pattern $h_d\ll h_s$ in the region of parameter space required to explain the top FBA, whereas our model for the CDF dijet anomaly is characterized by the absence of beyond the SM b-quark jets in the excess region. Compatibility of the color & weak triplet with the electroweak constraints is also discussed. We show that a Higgs boson mass exceeding the LEP bound is typically favored in this scenario, and that both Higgs production and decay can be significantly altered by the triplet. The most promising collider signature is found if the splitting among the components of the triplet is of weak scale magnitude.