# The minimal stealth boson: models and benchmarks

## TL;DR

This paper introduces minimal Standard Model extensions that produce stealth bosons, which are light boosted particles with cascade decays, and demonstrates that their signals could be significantly more detectable than traditional leptophobic Z' signals at the LHC.

## Contribution

It proposes minimal models with a new Z' boson and scalar singlets that generate stealth bosons, highlighting their potential for enhanced detection at colliders.

## Key findings

- Stealth boson signals can have up to nine times higher significance than standard Z' signals.
- Models include a leptophobic Z' and scalar singlets with anomaly cancellation.
- Results motivate model-independent searches for complex stealth boson signals.

## Abstract

Stealth bosons are relatively light boosted particles with a cascade decay $S \to A_1 A_2 \to q \bar q q \bar q$, reconstructed as a single fat jet. In this work, we establish minimal extensions of the Standard Model that allow for such processes. Namely, we consider models containing a new (leptophobic) neutral gauge boson $Z'$ and two scalar singlets, plus extra matter required to cancel the $\text{U}(1)'$ anomalies. Our analysis shows that, depending on the model and benchmark scenario, the expected statistical significance of stealth boson signals (yet uncovered by current searches at the Large Hadron Collider) is up to nine times larger than for the most sensitive of the standard leptophobic $Z'$ signals such as dijets, $t \bar t$ pairs or dibosons. These results provide strong motivation for model-independent searches that cover these complex signals.