$t\bar{t}t\bar{t}$ signatures through the lens of color-octet scalars

Abstract

We reinterpret two recent LHC searches for events containing four top quarks (t tt t) in the context of supersymmetric models with Dirac gauginos and color-octet scalars (sgluons). We explore whether sgluon contributions to the four-top production cross section σ(pp → t tt t) can accommodate an excess of four-top events recently reported by the ATLAS collaboration. We also study constraints on these models from an ATLAS search for new phenomena with jets and missing transverse energy (E miss T ) sensitive to signals with four top quarks. We find that these two analyses provide complementary constraints, with the jets + E miss T search exceeding the four-top cross section measurement in sensitivity for sgluons heavier than about 800 GeV. We ultimately find that either a scalar or a pseudoscalar sgluon can currently fit the ATLAS excess in a range of reasonable benchmark scenarios, though a pseudoscalar in minimal Dirac gaugino models is ruled out. We finally offer sensitivity projections for these analyses at the HL-LHC, mapping the 5σ discovery potential in sgluon parameter space and computing exclusion limits at 95% CL in scenarios where no excess is found.

Phenomenology of unusual top partners in composite Higgs models

“…(3.5). Their phenomenology has been widely studied, both in the case of composite models [37,38,40] and in effective and supersymmetric set-ups (sgluons) [65][66][67][68][69][70][71][72]. In the following we will assume that π 8 can either decay into t t and/or g g. 3 Current bounds on the π 8 mass from LHC searches for pair production with dominant decays into t t and gg lie at ∼ 1.05 TeV and ∼ 0.85 TeV, respectively, while bounds from single production are strongly model dependent [40].…”

Exploring the phenomenology of weak adjoint scalars in minimal $R$-symmetric models

“…Recently, particular attention has been paid to the strong sectors of such models and the interactions of the color-octet sgluons [10][11][12][13][14][15]. Here, we turn our attention to the weak sector and examine the behavior of the scalar singlet and SU (2) triplet fields.…”