Hitting two BSM particles with one lepton-jet: search for a top partner decaying to a dark photon, resulting in a lepton-jet

TL;DR

This paper proposes a novel search strategy for a top partner decaying into a dark photon, resulting in a distinctive lepton-jet signature, which can effectively suppress background at the LHC for masses up to 3 TeV.

Contribution

It introduces a new search method exploiting the unique topology of top partner decays to dark photons, enhancing detection prospects at the LHC.

Findings

Background can be nearly eliminated with specific kinematic cuts.

Signal remains detectable for top partner masses up to 3 TeV.

Effective in both hadronic and leptonic top decay channels.

Abstract

A maverick top partner model, decaying to a dark photon was suggested. The dark photon decays to two overlapping electrons for dark photon masses of $\approx 100$ GeV, and results in a so-called lepton-jet. The event includes a top quark as well, which results in events with two boosted objects, one heavy and the other light. We propose a search strategy exploiting the unique signal topology. We show that for a set of kinematic selections, both in hadronic and leptonic decay channel of the SM top quark, almost all background can be eliminated, leaving enough signal events up to top partner mass of about 3 TeV for the search to be viable at the LHC.