A hidden, heavier resonance of the Higgs field

Spontaneous symmetry breaking is an essential ingredient of the Standard Model. While Goldstone bosons are well understood, stillthe ultimate dynamical origin  of the phenomenon is not entirely clear. Given this uncertainty, one may wonder about the present view that the Higgs-field propagator has only one pole at 125 GeV. In fact, depending on the description of symmetry breaking, the effective potential, besides the mass scale describing its quadratic shape at the minima, could exhibit another mass scale associated with the zero-point energy, which determines its depth. Lattice simulations of the propagator are consistent with this two-mass structure and can be used to predict a new resonance around 700 GeV. In spite of its large mass, however, the heavier state would couple to longitudinal Ws with the same typical strength of the low-mass state and thus represent a relatively narrow resonance. In this way, such a hypothetical resonance would naturally fit with some excess of 4-lepton events observed by ATLAS around 680 GeV. Available CMS data in the same region, when grouped in bins of 30 GeV as done by ATLAS, are also consistent with this interpretation. Implications of this two-mass structure for radiative corrections will also be discussed.