Uncovering quasi-degenerate Kaluza-Klein Electro-Weak gauge bosons with top asymmetries at the LHC

TL;DR

This paper proposes a method to identify quasi-degenerate Kaluza-Klein electroweak gauge bosons at the LHC by analyzing charge and spin asymmetries in top-antitop events, offering a new way to distinguish complex resonant spectra.

Contribution

It introduces a novel approach combining charge and spin asymmetries in top-antitop final states to detect quasi-degenerate resonances in models with extra dimensions at the LHC.

Findings

Potential to detect multiple resonances at 14 TeV LHC with 100 fb^-1

Asymmetry observables can distinguish quasi-degenerate spectra from single resonances

Method complements traditional bump hunt analyses

Abstract

By exploiting the correlation between charge and spin polarisation asymmetries in t-tbar, we show that combining the two observables could identify the presence of quasi-degenerate states in a resonant signal at the LHC. As an example, we investigate experimental signatures emerging in top-antitop final states in the context of a model where the Standard Model Electro-Weak sector is allowed to propagate in large extra--dimensions of TeV^-1 size while the colour sector is localised. Assuming current experimantal constraints from the 7 and 8 TeV runs and taking into account the estimated top (anti-top) reconstruction efficiencies, we find that the 14 TeV upgraded LHC with the planned integrated luminosity L=100 fb^-1 could access these quasi-degenerate multiple resonances and explore for the first time the rich phenomenology in the asymmetry observables. The main outcome would be having measurable quantities, complementary to the usual total and differential cross sections, capable of distiguishing a quasi-degenerate multiply resonant spectrum from a `standard' single resonance that could present a similar signal in a bump hunt analysis.