Evasive maneuvers for a sequential fourth generation to circumvent the Higgs data

Abstract

So far, we have been unable to determine the sign of the down-type Yukawa couplings from the current Higgs data. We use this freedom to accommodate extra generations of fermions that obtain their masses through the exact same mechanism as the first three generations. Our recipe successfully hides the extra fermionic generations not only in the Higgs boson production through gluon fusion, but also in the loop induced Higgs decays like h → γγ and h → Zγ. We also illustrate how such hidden extra generation of fermions may unravel themselves in the di-Higgs production mechanisms.