Large Extra Dimension Effects on the Spin Configuration of the Top Quark Pair at e^+ e^- Colliders

TL;DR

This paper investigates how large extra dimensions and TeV-scale quantum gravity could alter the spin configurations of top quark pairs produced in electron-positron collisions, revealing significant deviations from Standard Model predictions.

Contribution

It introduces the impact of large extra dimensions on top quark spin states at e+e- colliders, highlighting observable deviations from the Standard Model.

Findings

Large extra dimensions induce significant deviations in top quark spin configurations.

Like-spin state cross sections become substantial, contrary to Standard Model predictions.

Angular cuts can effectively determine the sign of quantum gravity corrections.

Abstract

Large extra dimension effects on the spin configuration of the top quark pair at the $e^+ e^-\to t\bar{t}$ process are studied. It is shown that the TeV scale quantum gravity effects cause significant deviations from the Standard Model 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 $-0.5<\cos\theta<0$ is very effective to determine the sign of the quantum gravity corrections.