Reweighing the evidence for a light Higgs boson in dileptonic W boson decays.

We reconsider observables for discovering and measuring the mass of a Higgs boson via its dileptonic decays h → W W* → ℓνℓν. We define an observable generalizing the transverse mass that takes into account the fact that one of the intermediate W bosons is likely to be on shell. We compare this new variable with existing ones and argue that it gives a significant improvement for discovery in the region mh < 2 mW.