Polarized top pair production in extra dimension models via photon-photon fusion at the CERN LHC

We study the potential of processes pp -> p gamma gamma p -> pt (t) over barp in scenarios of the Arkani-Hamed-Dimopoulos-Dvali and the Randall-Sundrum model at the LHC. We obtain 95% C. L. bounds on the model parameters. We show top quark spin asymmetry can be detected and discerned from the standard model with these extra dimensional models.