Common exotic decays of top partners

Abstract

Many Standard Model extensions which address the hierarchy problem contain Dirac-fermion partners of the top quark at the TeV scale. We discuss several classes of composite Higgs models with top partners which have underlying descriptions in terms of a fundamental gauge-fermion dynamics. All of these models contain additional BSM states which are pseudo-Nambu-Goldstone bosons and are thus likely to be lighter than the top partners. We first discuss constraints from direct production and decay of these new states at the LHC and show that they can be light without conflicting with current searches. The pNGBs couple to top partners and thus provide new decay channels for them. We identify the novel top partner decays which occur most commonly in underlying models, provide effective Lagrangians and benchmarks, and discuss opportunities for future searches.