New Higgses at the Electroweak Scale and Differential 𝒕 𝒕 ¯ Distributions

Indications for new Higgs bosons at 95\,GeV and 152\,GeV with significance of $>3\sigma$ and $>4\sigma$, respectively, have been found. While the former mainly originates from the inclusive $\gamma\gamma$ channel, the latter is obtained by combining several modes of associated di-photon production, i.e.~$\gamma\gamma+X$ with $X=\ell,\,\ell b,\,{\rm MET},\,\tau,\,$etc. In particular, the Drell-Yan production $pp\to W^*\to H^0H^\pm$, either in the $\Delta$SM (the Standard Model extended by a real triplet) or a 2HDM can explain the 152\,GeV excess. The former option offers a connection to $t\bar t$ differential distributions, which show strong tensions with the SM predictions, since the experimental signature is $WW b\bar b$: A simplified model with a new scalar $H$, produced via gluon fusion and decaying to two neutral Higgses $S$ and $S^\prime$ with subsequent (dominant) decays to $WW$ and $b\bar b$, respectively, leads to the same final state. Since $WW$ is the dominant decay of a triplet Higgs with a mass around 152\,GeV, this motivates that the anomalies might be connected. Furthermore, assuming that $S^\prime$ is an $SU(2)_L$ singlet, the resulting di-photon signal strength is compatible with the 95\,GeV $\gamma\gamma$ measurements. A possible UV completion of this simplified model is the $\Delta$2HDMS, i.e.~a 2HDM supplemented with a singlet and a real triplet, which can successfully accommodate electroweak scale Baryogenesis.