Confronting the 95 GeV excesses within the U(1)'-extended next-to-minimal 2HDM

We consider the small excesses around 95 GeV found in several searches for a new scalar in gamma gamma, tau tau, and bb over bar final states. Instead of trying to accommodate them all, as is usually done in the literature, in the context of a given Standard Model (SM) extension, we investigate whether it would be possible that one or two of these excesses correspond to an actual new scalar, while the remaining ones are merely statistical fluctuations. To this end, we use as benchmark model the UN2HDM, a SM extension with one scalar doublet, one scalar singlet, and an extra U(1)' symmetry, which has been previously studied in the context of multiboson cascade decays. We show that most of the possibilities where the excesses in one or two of these channels disappear in the future can be accommodated by type-I or type-III UN2HDMs.

Automated summary

In this study, we investigate the possibility that one or two of the excesses found in the searches for a new scalar could correspond to an actual new scalar, while the remaining ones are statistical fluctuations. We use the UN2HDM as a benchmark model and show that type-I or type-III UN2HDMs can explain most of the cases where the excesses in one or two of these channels disappear in the future.