Boosting vector leptoquark searches with boosted tops
Arvind Bhaskar, Tanumoy Mandal, Subhadip Mitra
At the LHC, a TeV-scale leptoquark (LQ) that decays dominantly to a top quark (t) and a light charged lepton (ℓ=e,μ) would form a resonance system of boosted-t + high-pT-ℓ. We consider all possible vector LQ models within the Buchmüller-Rückl-Wyler classifications with the desired decay. We propose simple phenomenological Lagrangians that are suitable for bottom-up/experimental studies and, at the same time, can cover the relevant parameter spaces of these models. In this simplified framework, we study the pair and single production channels of vector LQs at the LHC. Interestingly, we find that, like the pair production, the cross sections of some single production processes also depend on the parameter κ that appears in the gluon-vector LQ coupling. We adopt a search strategy of selecting events with at least one boosted hadronic top quark and exactly two high-pT leptons of the same flavor and opposite sign. This combines events from the pair and single production processes and, therefore, can enhance the discovery potential than that of the pair-production-only searches. For 5σ discovery we find that vector LQs can be probed up to 2.55 TeV for 100% branching ratio in the tℓ decay mode and O(1) new couplings at the 14 TeV LHC with 3 ab−1 of integrated luminosity.