Searching for Low-Mass Resonances Decaying into $W$ Bosons

Abstract

In this article, we recast and combine the CMS and ATLAS analyses of the Standard Model Higgs boson decaying to a pair of $W$ bosons in order to search for low-mass resonances in this channel. We provide limits on the corresponding cross section assuming direct production via gluon fusion. For the whole range of masses we consider (90GeV to 200GeV), the observed limit on the cross section turns out to be weaker than the expected one. Furthermore, at $\approx 95$GeV the limit is weakest and a new scalar decaying into a pair of $W$ bosons (which subsequently decay leptonically) with a cross section $\approx 0.5$pb is preferred over the Standard Model hypothesis by $\gtrsim 2.5\sigma$. In light of the excesses in the $\gamma \gamma$, ${\tau }^{+}{\tau }^{-}$ and $b\bar{b}$ channels at similar masses, this strengthens the case for such a new Higgs boson. Furthermore, this analysis also gives room for the scalar candidate at 151GeV decaying into $W$ bosons.

Comments: 7 pages, 5 figures, 1 table, version accepted for publication in PRD