Has a fermiophobic Higgs boson been detected at the LHC?

Abstract

We show that, in the present inclusive searches for the Higgs boson at the LHC, a fermiophobic Higgs mimics the standard-model-like Higgs if its mass is around 125 GeV. For that mass the order-of-magnitude reduction of fermiophobic Higgs production cross sections is compensated by a corresponding increase in the Higgs branching fraction into $γγ$, while the $WW^*,$ $ZZ^*,$ $Zγ$ signal yields are predicted to be somewhat smaller. The excess seen in the ATLAS and CMS fermiophobic Higgs boson searches in $γγ$ channel, including the exclusive vector-boson-fusion analysis, suggests that the LHC sees a fermiophobic instead of a standard-model-like Higgs boson. If the Higgs boson turns out to be fermiophobic, many of our present ideas of new physics should be revised.

Figures (2)

• Figure 1: Dependence of the inclusive cross-sections times branching fraction for the FP Higgs boson decays into $\gamma\gamma,$$WW^*,$$ZZ^*$ and $Z\gamma$ (from up to down) on the Higgs mass $m_H$ at 7 TeV LHC. Dash-dotted lines stand for the plain FP model, while red continuous lines represent the FP model with the inclusion of radiative corrections for several values of the new-physics scale $\Lambda=10^{4,6,10,16}$ GeV. The dotted lines present the central values of the SM Higgs inclusive production, together with the theoretical error shown by the green band.
• Figure 2: Relative magnitudes of the FP Higgs prediction over a SM-like Higgs in different channels at the 7 TeV LHC for $m_H=122,\,124,\,126$ GeV. The error bars correspond to the SM cross section uncertainties. The red (upper) and blue (lower) predictions show the theoretical errors associated with the new-physics scale $\Lambda.$ For LHC at 8 TeV, the results are practically identical.