English

Multi-top signals of vectorlike quarks at the LHC

High Energy Physics - Phenomenology 2025-12-17 v2 High Energy Physics - Experiment

Abstract

We point out that events with 6 or more top quarks may be observed at the LHC if certain particles exist at the TeV scale. In a model where a vectorlike quark of charge 2/3 decays into a top quark and a pseudoscalar particle, which subsequently decays into a top-antitop pair, the LHC production cross section for events with 6 top quarks may be above 10 fb. If the pseudoscalar is part of a complex scalar field, then longer cascade decays, involving the scalar partner, may lead to events with 8 or even 10 top quarks. We show that for a region of parameter space the dominant LHC signal in this model is 8 top quarks (i.e., four ttˉt\bar t pairs). The ensuing signals would be spectacular, including many leptons and bb jets. A discovery in that case would allow several cross section measurements that may determine the masses of all three new particles.

Keywords

Cite

@article{arxiv.2508.14960,
  title  = {Multi-top signals of vectorlike quarks at the LHC},
  author = {Elias Bernreuther and Bogdan A. Dobrescu},
  journal= {arXiv preprint arXiv:2508.14960},
  year   = {2025}
}

Comments

27 pages, 7 figures; v2: included table with branching fractions for the top-prime quark, added references, matches published version