Stopping Dark Mesons in Their Tracks with Long-Lived Particle and Resonant Signatures

TL;DR

This paper explores collider signatures of dark mesons from confining dark sectors, recasting LHC searches to set bounds on their masses and interactions, and highlighting potential for future discoveries.

Contribution

It introduces novel reinterpretations of LHC searches for long-lived dark mesons and anomalous diboson signals, providing new bounds and insights into dark sector parameters.

Findings

Charged dark mesons are constrained to have masses above ~1.2 TeV.

The 5-plet dark mesons interact via a chiral anomaly, leading to diboson resonance signatures.

Future measurements could determine dark sector parameters from infrared states.

Abstract

Dark sectors with confining gauge interactions can provide both simple dark matter candidates and striking signals at colliders. We recast Large Hadron Collider searches for two different signatures of dark mesons that arise from a strongly-coupled theory with vector-like dark quarks that are in some non-trivial representation of Standard Model SU(2)$_L$. For any such electroweak representation, there is a 3-plet of dark mesons whose charged components are long-lived, and we reinterpret searches for disappearing tracks to place a lower bound on their mass of $\sim 1.2$ TeV. When the dark quarks are in SU(2)$_L$ representations larger than the fundamental, there is also a 5-plet of dark mesons that interacts with the electroweak gauge bosons via a chiral anomaly. We show that the 5-plet is the unique non-trivial meson multiplet with this anomaly and recast searches for the resulting diboson resonances to place bounds on model parameters. With additional measurements, the anomaly also enables one to reconstruct some ultraviolet parameters (the numbers of dark flavors and colors) while only measuring states in the infrared. Each of these signals represents an exciting opportunity for future searches using higher luminosity.