Speaker
Description
The CMS collaboration has recently reported the final Run 2 results of the low-mass Higgs-boson search in the di-photon channel. The new results show an excess of events at a mass of about 95 GeV with a local significance of $2.9\sigma$, confirming a previously reported excess at about the same mass and similar significance based on the first-year Run 2 plus Run 1 data. In this work, we discuss the diphoton excess and show that it can be interpreted as the lightest Higgs boson in the Two-Higgs doublet model that is extended by a complex singlet (S2HDM) of Yukawa types II and IV. We show that the second-lightest Higgs boson is in good agreement with the current LHC Higgs-boson measurements of the state at 125 GeV, and that the full scalar sector is compatible with all theoretical and experimental constraints. Furthermore, we discuss the diphoton excess in conjunction with an excess in the $b \bar b$ final state observed at LEP and an excess observed by CMS in the ditau final state, which were found at comparable masses with local significances of about $2\sigma$ and $3\sigma$, respectively. We find that the
$b \bar b$ excess can be well described together with the diphoton excess in both types of the S2HDM. However, the ditau excess can only be accommodated at the level of $1\sigma$ in type IV.
| Collaboration / Activity | None |
|---|
