Getting to the top with extra dimensions

The prospect of large extra dimensions and an effective theory of gravity at around a TeV has interesting experimental consequences. In these models, the Kaluza–Klein modes interact with Standard Model particles and these interactions lead to testable predictions at present and planned colliders. We investigate the effect of virtual exchanges of the spin-2 Kaluza–Klein modes in the production cross-section of tt̄ pairs at the Tevatron and the LHC and find that the tt̄ cross-section can be an effective probe of the large extra dimensions. This enables us to put bounds on the effective low-energy scale.