Are there really any experimental limits on a light Higgs boson?

Abstract

The experimental evidence regarding a light Higgs boson is reviewed. It is shown that a light Higgs boson with almost any mass between 14 MeV/$c^2$ and 1 GeV/$c^2$ is still allowed by existing data. The only limit in this range comes from B-decay data which, for sufficiently large values of the top-quark mass, excludes a Higgs boson with a mass between 2$m_{\mu }$ and ∼700 MeV/$c^2$. Discussions of light-Higgs-boson emission in the decays of K, π, μ, τ, η’, and Υ are also given.