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

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 (90$$GeV to 200$$GeV), 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 151$$GeV decaying into $W$ bosons.