  In theories with large extra dimensions, we study the top spin correlations
at the Large Hadron Collider. The s-channel process mediated by graviton
Kaluza-Klein modes contributes to the top-antitop pair production in addition
to the Standard Model processes, and affects the resultant top spin
correlations. We calculated the full density matrix for the top-antitop pair
production. With the fundamental scale of the extra dimensional theory below 2
TeV, we find a sizable deviation of the top spin correlations from the Standard
Model one.

High Energy Physics - Phenomenology