Large extra dimension effects on the spin configuration of the top quark pair ate+e−colliders

Large extra dimension effects on the spin configuration of the top quark pair at the $e^{+}{e}^{-}\to t\overline{t}$ process are studied. It is shown that the TeV scale quantum gravity effects cause significant deviations from standard model (SM) predictions for the spin configuration in the off-diagonal basis: they lead to substantial cross sections of the like-spin states of the top quark pair, which vanish in the SM; they weaken the pure dominance of the processes, the up-down (down-up) spin states for the left-handed (right-handed) beam. In addition it is shown that the angular cut $-0.5<\mathrm{}\cos \theta <0\mathrm{}$ is very effective to determine the sign of the quantum gravity corrections.