Effective field theory for vector-like leptons and its collider signals
Mikael Chala, Paweł Kozów, Maria Ramos, Arsenii Titov
We demonstrate that vector-like leptons in models with several high scales; e.g. in composite Higgs models, are likely produced in a relatively large √s region of the phase space. Likewise, they can easily decay into final states not containing Standard Model gauge bosons. This contrasts with the topology in which these new particles are being searched for at the LHC. Adopting an effective field theory approach, we show that searches for excited leptons must be used instead to test this scenario. We derive bounds on all the relevant interactions of dimension six; the most constrained ones being of about 0.05 TeV−2. We build new observables to improve current analyses and study the impact on all single-field UV completions of the Standard Model extended with a vector-like lepton that can be captured by the effective field theory at tree level, in the current and in the high-luminosity phase of the LHC.