Identifying boosted new physics with non-isolated leptons

TL;DR

This paper explores the use of non-isolated leptons, which are typically ignored, as a new way to detect boosted new physics signals at the LHC, employing jet substructure techniques to improve discrimination.

Contribution

It introduces a novel approach using jet substructure to identify non-isolated leptons, enhancing search strategies for new physics like R-parity violating supersymmetry.

Findings

Non-isolated leptons can signal new physics events missed by standard methods.

Jet substructure variables outperform existing techniques in distinguishing signals from background.

The approach extends the experimental reach for detecting boosted new physics at the LHC.

Abstract

We demonstrate the utility of leptons which fail standard isolation criteria in searches for new physics at the LHC. Such leptons can arise in any event containing a highly boosted particle which decays to both leptons and quarks. We begin by considering multiple extensions to the Standard Model which primarily lead to events with non-isolated leptons and are therefore missed by current search strategies. We emphasize the failure of standard isolation variables to adequately discriminate between signal and SM background for any value of the isolation cuts. We then introduce a new approach which makes use of jet substructure techniques to distinguish a broad range of signals from QCD events. We proceed with a simulated, proof-of-principle search for R-parity violating supersymmetry to demonstrate both the experimental reach possible with the use of non-isolated leptons and the utility of new substructure variables over existing techniques