Paper

Octet scalars shaping LHC distributions in 4-jet final states

Fieg, Max H, Dobrescu, Bogdan A

2025

Overview

We study properties of a hypothetical scalar particle, \\(\\), which is a color octet and an electroweak singlet. At hadron colliders, \\(\\) is pair produced through its QCD coupling to gluons, so that its mass determines the cross section. It decays at tree level into \\(q q\\) through dimension-5 operators, and at one loop into gluons. Thus, the main LHC signature of \\(\\) is a pair of dijets of equal invariant mass. The CMS search in this channel shows a \\(3.6\\) excess over the QCD background for a dijet mass \\(M_jj 0.95\\) TeV, which can be due to \\(\\): its production cross section (65 fb for a real scalar) and the acceptance of the CMS event selection applied to \\(p p \\! (q q)(q q)\\) yield a rate consistent with the excess. Furthermore, the shape of the \\(d/d M_jj\\) signal is in agreement with the CMS result. Given the data-driven background fit performed by CMS, we find that a complex scalar fits better the data than a real scalar. Besides the pair of dijets, testable LHC signals include a trijet-dijet topology, a \\(t t\\) pair plus a dijet resonance, as well as final states involving a Higgs, \\(W\\) or \\(Z\\) boson plus jets.

• Publisher: Cornell University Library, arXiv.org
• Subject: Cross-sections / Gluons / Large Hadron Collider / Quantum chromodynamics / Scalars / Topology