Virginia TechLoinaz, WilliamOkamura, NaotoshiTakeuchi, TatsuWijewardhana, L. C. R.2013-12-182013-12-182003-04Loinaz, W ; Okamura, N ; Takeuchi, T ; et al., APR 2003. “NuTeV anomaly, neutrino mixing, and a heavy Higgs boson,” PHYSICAL REVIEW D 67(7): 073012. DOI: 10.1103/PhysRevD.67.0730121550-7998http://hdl.handle.net/10919/24754Recent results from the NuTeV experiment at Fermilab and the deviation of the Z invisible width, measured at CERN LEP and the SLAC Linear Collider, from its standard model (SM) prediction suggest the suppression of neutrino-Z couplings. Such suppressions occur naturally in models which mix the neutrinos with heavy gauge singlet states. We postulate a universal suppression of the Znunu couplings by a factor of (1-epsilon) and perform a fit to the Z-pole and NuTeV observables with epsilon and the oblique correction parameters S and T. Compared to a fit with S and T only, the inclusion of epsilon leads to a dramatic improvement in the quality of the fit. The values of S and T preferred by the fit can be obtained within the SM by a simple increase in the Higgs boson mass. However, if the W mass is also included in the fit, a non-zero U parameter becomes necessary which cannot be supplied within the SM. The preferred value of epsilon suggests that the seesaw mechanism may not be the reason why neutrinos are so light.en-USIn Copyrightfermion pair productionsupersymmetric standard modelextradimensionssin(2) theta(w)qed correctionsmassannihilationoscillationparameterscalculateAstronomy & AstrophysicsPhysicsArticle - Refereedhttp://link.aps.org/doi/10.1103/PhysRevD.67.073012https://doi.org/10.1103/PhysRevD.67.073012