B Anomalies and Leptoquarks at the LHC: Beyond the Lepton-Quark Final State

TL;DR

This paper explores how composite dynamics can alter leptoquark collider signatures, leading to more complex final states and relaxed experimental bounds, with implications for explaining B decay anomalies.

Contribution

It introduces a novel scenario where composite dynamics produce additional states, changing leptoquark signatures and allowing lighter masses consistent with current collider limits.

Findings

Leptoquarks can produce up to four jets and a lepton in collider events.

Current ATLAS and CMS searches can be reinterpreted to relax bounds on leptoquark masses.

A leptoquark related to the R_D(*) anomaly could be as light as 500 GeV.

Abstract

Leptoquarks provide some of the simplest explanations to the hints of lepton flavor non-universality in $B$ decays. In particular, a new confining gauge group can provide a natural and appealing origin for the leptoquarks. So far, direct collider searches have been based on two body decays, namely to a quark and a lepton. We study how composite dynamics can give rise to additional states resulting in modified collider signatures of leptoquarks, as well as new production modes in cascade decays of heavier states. Instead of the standard signature, each leptoquark can result in as many as four jets and a lepton. We reinterpret relevant ATLAS and CMS searches to set limits on this scenario, show how this can relax the current bounds, and propose ways to better constrain this class of models in the future. For example, we show that a leptoquark related to the $R_{D^{(*)}}$ anomaly could still be as light as 500 GeV.