We examine the decays of heavy ${\mathrm{SU}\mathrm{}\left(2\right)\mathrm{}}_L$-singlet quarks to a Higgs boson and a light quark in a class of ${\mathrm{E}}_6$ electroweak models with more than one Higgs multiplet. We calculate the branching fractions for several scenarios involving different Higgs sectors and quark mixing. We find that the enhanced couplings and decays to charged and pseudoscalar Higgs bosons can significantly increase the overall branching fraction to Higgs bosons. The increased Higgs-boson production rate improves the detection possibilities at hadron colliders of higher-mass Higgs bosons.

• Received 15 September 1989

DOI:https://doi.org/10.1103/PhysRevD.41.2120