Four tops on the real projective plane at LHC

Abstract

We explore the four top signal tt̄tt̄ at the 7TeV Large Hadron Collider as a probe of physics beyond the standard model. Enhancement of the corresponding crosssection with respect to the Standard Model value can probe the electroweak symmetry breaking sector or test extra dimensional models with heavy Kaluza-Klein gluons and quarks. We perform a detailed analysis including background and detector simulation in the specific case of a universal extra-dimensional model with two extra dimensions compactified using the geometry of the real projective plane. For masses around 600GeV, a discovery is possible for an effective cross section above 210 fb (36 fb) for 1/fb (10/fb) of integrated luminosity. This implies a branching ratio in tops of the (1, 1) heavy photon above 13% (5%). Furthermore, the 4-top signal from the (2, 0) and (0, 2) tiers can be discovered with an integrated luminosity of 3.5/fb. The results of our simulation can be easily adapted to other models since the background processes are identical. Concerning the signal, typical production mechanisms for the tt̄tt̄ signal are similar even if cross-section values may vary considerably depending on the model and the spectrum of the new particles.