We analyze the phenomenology of the top-pion and top-Higgs states in models with strong top dynamics, and translate the present LHC searches for the Standard Model Higgs into bounds on these scalar states. We explore the possibility that the new state at a mass of approximately 125 GeV observed at the LHC is consistent with a neutral pseudoscalar top-pion state. We demonstrate that a neutral pseudoscalar top pion can generate the diphoton signal at the observed rate. However, the region of model parameter space where this is the case does not correspond to classic top-color-assisted technicolor scenarios with degenerate charged and neutral top pions and a top-Higgs mass of order $2m_t$; rather, additional isospin violation would need to be present and the top dynamics would be more akin to that in top seesaw models. Moreover, the interpretation of the new state as a top pion can be sustained only if the $ZZ$ (four-lepton) and $WW$ (two-lepton plus missing energy) signatures initially observed at the $3\sigma$ level decline in significance as additional data are accrued.

• Received 2 July 2012

DOI:https://doi.org/10.1103/PhysRevD.86.095017