The $R_b$ Excess at LEP: Clue to New Physics at the TEVATRON?
arXiv:hep-ph/9505268 · doi:10.1063/1.49317
Abstract
If the $R_b$ excess at LEP is real, then any explanation in terms of renormalizable loop corrections leads to important new decay modes of the $t$ quark and suppresses the $t \to bW$ branching ratio. In the two-Higgs-doublet model, the branching ratio of $Z \to b \bar b$ + a light boson which decays itself predominantly into $b \bar b$ is at least of order $10^{-4}$.
4 pages, 3 figures