Emerging Jets

TL;DR

This paper introduces a new LHC search method for detecting emerging jets indicative of a dark sector with displaced decays, significantly enhancing sensitivity to certain long-lived particle models.

Contribution

It proposes a novel search strategy for emerging jets from dark sector models, with detailed simulation and background suppression techniques, extending LHC sensitivity to higher mediator masses.

Findings

Can probe mediator masses up to 1.5 TeV at 14 TeV LHC

Achieves background suppression by up to six orders of magnitude

Sensitive to broad class of long-lived phenomena, including R-parity violating SUSY

Abstract

In this work, we propose a novel search strategy for new physics at the LHC that utilizes calorimeter jets that (i) are composed dominantly of displaced tracks and (ii) have many different vertices within the jet cone. Such emerging jet signatures are smoking guns for models with a composite dark sector where a parton shower in the dark sector is followed by displaced decays of dark pions back to SM jets. No current LHC searches are sensitive to this type of phenomenology. We perform a detailed simulation for a benchmark signal with two regular and two emerging jets, and present and implement strategies to suppress QCD backgrounds by up to six orders of magnitude. At the 14 TeV LHC, this signature can be probed with mediator masses as large as 1.5 TeV for a range of dark pion lifetimes, and the reach is increased further at the high-luminosity LHC. The emerging jet search is also sensitive to a broad class of long-lived phenomena, and we show this for a supersymmetric model with R-parity violation. Possibilities for discovery at LHCb are also discussed.