A heavy little Higgs and a light Z' under the radar

Abstract

The original littlest Higgs model with universal fermion couplings is found to be consistent with precision electroweak data but is strongly constrained by Tevatron limits on the predicted centi-weak Z' boson. A possible signal observed by CDF at 240 GeV is consistent with the predicted Z' and a region below 150 GeV is largely unconstrained by collider data.

Comments: 14 pages, 3 figures. Version 2 corrects coding error for Moller scattering and includes effect of Z-Z' mixing on Z' decays, with small changes in results. Added new figures, tables, and citations. Version 3 is as published in PRD, adds discussion of fine tuning of model parameters