Effect of spin-3/2 top quark excitation on ttbar production at the LHC

TL;DR

This paper investigates how a hypothetical spin-3/2 top quark excitation, predicted by string-inspired models, affects top-antitop production at the LHC, providing insights into potential signals of new physics beyond the Standard Model.

Contribution

It analyzes the impact of a spin-3/2 top excitation on ttbar production cross sections and distributions, comparing it with other BSM scenarios and exploring discovery prospects at different LHC energies.

Findings

Significant increase in ttbar cross section at higher energies.

Distinct observable distributions for different BSM scenarios.

Extended discovery reach with increasing collider energy.

Abstract

A spin-3/2 top quark excitation originating in string realisations of the RS scenario has an effect on the production of top-antitop pairs in hadron-hadron collisions. We study the additional contribution of this state to the cross section for the LHC. We comment on the prospect of discovery or exclusion for a range of masses and couplings at both 7 and 14 TeV and show that the reach extends significantly with increasing centre-of-mass energy. Results are compared with the effect of a hypothetical spin-1/2 excited top as well as other BSM scenarios which predict the presence of higher dimension effective operators. We also calculate distributions for several observables which can be used to distinguish between the different scenarios in the presence of a deviation from the SM prediction for the ttbar cross section.