Boosted top quark inspired leptoquark searches at the muon collider

TL;DR

This paper explores the potential of a muon collider to discover scalar leptoquarks decaying into top quarks and muons, demonstrating that combining pair and single production modes extends the mass reach significantly.

Contribution

It introduces a combined analysis of pair and single leptoquark production at a muon collider, enhancing discovery prospects for heavy scalar leptoquarks decaying into top quarks.

Findings

Single production can probe leptoquarks up to 4.5 TeV at 5 TeV collider.

Combined production modes extend the mass reach to 9.0 TeV at 10 TeV collider.

Boosted top jet signatures are key to identifying heavy leptoquarks.

Abstract

The proposed muon collider presents a promising avenue to explore various classes of beyond the Standard Model (BSM) particles. In this paper, we investigate the discovery prospects of the scalar leptoquark (LQ) $S_1$ at a muon collider. We consider two benchmark center-of-mass (C.O.M.) energy scenarios: 5 TeV and 10 TeV. We assume that the LQ decays into a top quark and a muon. The collider analysis for an LQ decaying into a top quark is distinct from that of lighter quarks. A TeV-scale LQ decaying into a top quark can produce an exotic, boosted fat-jet signature. In addition to the usual searches based on pair production of LQs, we also examine the single production mode, which depends on the $S_1 t \mu$ coupling. We demonstrate that systematically combining the pair and single production modes significantly enhances the discovery potential of the LQ at the muon collider. Our signal topology includes at least one hadronically decaying top fat-jet and two oppositely charged muons, thereby enabling the incorporation of the single production mode. We show that even with single production alone, it is possible to probe LQs as heavy as 4.5 TeV (9.0 TeV) in the 5 TeV (10 TeV) C.O.M. scenario for $\mathcal{O}(1)$ couplings.