Searching for sgluons in multitop events at a center-of-mass energy of 8 TeV

TL;DR

This paper investigates the potential to detect sgluons, hypothetical scalar particles predicted by certain new physics models, through multitop events at the LHC operating at 8 TeV, establishing exclusion limits and mass reach.

Contribution

It introduces a simplified effective field theory for sgluons decaying into top quarks and analyzes the LHC's sensitivity to these particles in multitop final states.

Findings

Sgluon-induced cross sections as low as 10-100 fb can be excluded.

Sgluon masses of about 500-700 GeV are reachable.

The analysis covers multilepton and single lepton channels.

Abstract

Large classes of new physics theories predict the existence of new scalar states, commonly dubbed sgluons, lying in the adjoint representation of the QCD gauge group. Since these new fields are expected to decay into colored Standard Model particles, and in particular into one or two top quarks, these theories predict a possible enhancement of the hadroproduction rate associated with multitop final states. We therefore investigate multitop events produced at the Large Hadron Collider, running at a center-of-mass energy of 8 TeV, and employ those events to probe the possible existence of color adjoint scalar particles. We first construct a simplified effective field theory motivated by R-symmetric supersymmetric models where sgluon fields decay dominantly into top quarks. We then use this model to analyze the sensitivity of the Large Hadron Collider in both a multilepton plus jets and a single lepton plus jets channel. After having based our event selection strategy on the possible presence of two, three and four top quarks in the final state, we find that sgluon-induced new physics contributions to multitop cross sections as low as 10-100 fb can be excluded at the 95% confidence level, assuming an integrated luminosity of 20 inverse fb. Equivalently, sgluon masses of about 500-700 GeV can be reached for several classes of benchmark scenarios.