EPS-HEP2021 conference

26-30 July 2021
Zoom
Europe/Berlin timezone

Possible indications for new Higgs bosons in the reach of the LHC: N2HDM and NMSSM interpretations

26 Jul 2021, 16:30
15m
Zoom

Zoom

Parallel session talk Searches for New Physics

Speaker

Thomas Biekoetter (T (Phenomenology))

Description

In several searches for additional Higgs bosons at the LHC, in particular the CMS search in the $pp \to \phi \to t \bar t$ channel and the ATLAS search in the $pp \to \phi \to \tau^+\tau^-$ channel, a local excess at the level of $3\,\sigma$ or above has been observed at a mass scale of $m_\phi \approx 400$~GeV. We investigate to what extent a possible signal in those channels could be accommodated in the Next-to-Two-Higgs-Doublet Model (N2HDM) or the Next-to Minimal Supersymmetric Standard Model (NMSSM). In a second step we furthermore analyse whether such a model could be compatible with both a signal at $\approx 400$~GeV and at $\approx 96$~GeV, where the latter possibility is motivated by observed excesses in searches for the $b \bar b$ final state at LEP and the di-photon final state at CMS. The analysis for the N2HDM reveals that the observed excesses at $\approx 400$~GeV in the observed excesses at $\approx 400$~GeV in the $pp \to \phi \to t \bar t$ and $pp \to \phi \to \tau^+\tau^-$ channels point towards different regions of the parameter space, while one such excess and an additional Higgs boson at $\approx 96$~GeV could simultaneously be accommodated. In the context of the NMSSM an experimental confirmation of a signal in the $t \bar t$ final state would favor the alignment-without-decoupling limit of the model, where the Higgs boson at $\approx 125$~GeV could be essentially indistinguishable from the Higgs boson of the SM. In contrast, a signal in the $\tau^+\tau^-$ channel would be correlated with significant deviations of the properties of the Higgs boson at $\approx 125$~GeV from the ones of a SM Higgs boson that could be detected with high-precision coupling measurements.

Collaboration / Activity theory Sven Heinemeyer Sven.Heinemeyer@cern.ch

Primary authors

Sven Heinemeyer (IFCA (CSIC, Santander)) Georg Weiglein (T (Phenomenology)) Thomas Biekoetter (T (Phenomenology)) Christian Schwanenberger (CMS (CMS Fachgruppe TOP)) Alexander Grohsjean (CMS (CMS Fachgruppe TOP))