The Lepton-Gluon Portal Beyond Lepto-Gluons

TL;DR

The paper investigates the lepton-gluon portal as a general EFT pathway to access light exotic BSM states, constructing a complete basis of operators up to dimension 6 (with selected dimension-7 additions) that couple a single LEX state to the SM via at least one lepton and one gluon. It systematically classifies the resulting exotic representations, including color octets, sextets, 15-plets, and bi-adjoints, and details how Higgs insertions and electroweak symmetry breaking generate additional couplings and mass splittings. The authors also explore LHC phenomenology for exotic color-octet fermions (leptogluons), computing production cross sections for several models and showing potential signals such as lepton-associated production and monojet signatures up to masses around 1.4 TeV with Λ ≈ 5 TeV. This framework broadens the collider search space for BSM exotics, guiding HL-LHC studies and motivating model-building efforts in the octet sector and beyond.

Abstract

We explore models where single new exotic states interact with the Standard Model through an asymmetric Standard Model portal with couplings to at least one gluon and one lepton. We consider the complete set of effective operators up to dimension 6, and examine a few additional dimension 7 operators that contain interesting field content or potential collider signals. The lepton-gluon portal allows access to exotic states with an interesting range of SU(3) and SU(2) quantum numbers. Finally, we explore potential single-production modes and their phenomenological signatures at colliders.