Phenomenology of the heavy B in a littlest Higgs model

We comprehensively study in the littlest Higgs model the phenomenology of the heavy U(1) gauge boson B, which is the lightest of the newly introduced heavy gauge bosons and toplike vector quarks. Some unexpected behavior is that in the parameter space where the mass of B is minimized the corrections to the electroweak precision observables are also suppressed. For the global symmetry breaking scale f ≤ 3 TeV, the B is light enough to be produced at a 500 GeV linear collider. We show that this light B is not excluded by the direct search for the neutral heavy gauge boson at the Fermilab Tevatron in a large portion of the parameter space. Furthermore, even the light B with a mass around 200 GeV yields negligible contributions to the muon anomalous magnetic moment, which is consistent with the current inconclusive status of the theoretical calculation of (g - 2) in the standard model. The effects of the littlest Higgs model on the ee → μμ process are also studied; this is one of the most efficient processes to probe the B. ©2004 The American Physical Society.