Accommodating hints of new heavy scalars in the framework of the flavor-aligned two-Higgs-doublet model

Searches for new neutral Higgs bosons of an extended Higgs sector at the LHC can be interpreted in the framework of the two-Higgs doublet model. By employing generic flavor-aligned Higgs-fermion Yukawa couplings, we propose an analysis that uses experimental data to determine whether flavor alignment is a consequence of a symmetry that is either exact or at most softly broken. We illustrate our proposal in two different scenarios based on a few 3 sigma (local) excesses observed by the ATLAS and CMS Collaborations in their searches for heavy scalars. In scenario 1, an excess of events is interpreted as A -> ZH -> l+l-bb over bar (where l = e or mu), with the CP-odd and CP-even neutral scalar masses given by mA = 610 GeV and mH = 290 GeV, respectively. In scenario 2, an excess of events in the production of tt over bar and tau+tau- final states is interpreted as decays of a CP-odd scalar of mass mA = 400 GeV. Scenario 1 is consistent with type-I Yukawa interactions, which can arise in a 2HDM subject to a softly-broken Z2 discrete symmetry. Scenario 2 is inconsistent with a symmetry-based flavor alignment, but can be consistent with more general flavor-aligned Higgs-fermion Yukawa couplings.