Z' Bosons, the NuTeV Anomaly, and the Higgs Boson Mass

TL;DR

This paper explores how Z' bosons in certain U(1) extensions of the Standard Model can reconcile the Higgs boson mass with experimental bounds and improve fit quality when including NuTeV data.

Contribution

It demonstrates that specific Z' models can significantly increase the predicted Higgs mass and enhance fit confidence levels, especially when incorporating NuTeV measurements.

Findings

Z' models can raise the Higgs mass prediction from ~60 to ~120 GeV.

Including NuTeV data improves the fit and the effect of Z' models.

Revised NuTeV estimates further strengthen the results.

Abstract

Fits to the precision electroweak data that include the NuTeV measurement are considered in family universal, anomaly free U(1) extensions of the Standard Model. In data sets from which the hadronic asymmetries are excluded, some of the Z' models can double the predicted value of the Higgs boson mass, from ~ 60 to ~ 120 GeV, removing the tension with the LEP II lower bound, while also modestly improving the chi-square confidence level. The effect of the Z' models on both the Higgs boson mass and the chi-square confidence level is increased when the NuTeV measurment is included in the fit. Both the original NuTeV data and a revised estimate by the PDG are considered.