LHC Signatures of Two-Higgs-Doublets with Fourth Family

TL;DR

This paper investigates how a two-Higgs-doublet model with a fourth family of fermions can explain the LHC's observed excesses in gamma-gamma and VV* channels around 124-126 GeV, suggesting invisible decays to neutrinos as a key factor.

Contribution

It introduces a model with a fourth fermion family and Higgs decays to neutrinos to account for LHC Higgs signals, offering a novel explanation for observed excesses.

Findings

The model can explain the LHC excesses in gamma-gamma and VV* channels.

Invisible Higgs decays to fourth-family neutrinos are crucial for matching observations.

Predictions will be tested in upcoming LHC runs in 2012.

Abstract

On-going Higgs searches in the light mass window are of vital importance for testing the Higgs mechanism and probing new physics beyond the standard model (SM). The latest ATLAS and CMS searches for the SM Higgs boson at the LHC (7TeV) found some intriguing excesses of events in the \gamma\gamma/VV^* channels (V=Z,W) around the mass-range of 124-126 GeV. We explore a possible explanation of the \gamma\gamma and VV^* signals from the light CP-odd Higgs A^0 or CP-even Higgs h^0 from the general two-Higgs-doublet model with fourth-family fermions. We demonstrate that by including invisible decays of the Higgs boson A^0 or h^0 to fourth-family neutrinos, the predicted \gamma\gamma and VV^* signals can explain the observed new signatures at the LHC, and will be further probed by the forthcoming LHC runs in 2012.