The minimal stealth boson: models and benchmarks

Stealth bosons are relatively light boosted particles with a cascade decay S -> A1A2 -> qqqq, reconstructed as a single fat jet. In this work, we establish mini- mal extensions of the Standard Model that allow for such processes. Namely, we consider models containing a new (leptophobic) neutral gauge boson Z(t) and two scalar singlets, plus extra matter required to cancel the U(1)(t) 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(t) signals such as dijets, tt degrees pairs or dibosons. These results provide strong motivation for model-independent searches that cover these complex signals.