Investigation of Entangled and Bound ttbar Pairs at the LHC with the CMS Detector

The top-antitop quark system offers a unique window into quantum information at the LHC. The mass of the top quark causes the top quark to have an exceptionally short lifetime before decaying. It is so short that typical estimates for the time scale for hadronization and spin-flip for the top quark are longer than the decay time. Therefore, we can use the top-antitop system to probe entanglement in an elementary particle system at energy scales previously unexplored in quantum information theory. On a related note, recently deviations in the low m_{ttbar} region have been observed by both ATLAS and CMS for dileptonic decays of the top-antitop system. One possible explanation for this would be the formation of a top-antitop bound state - toponium. This would alter the spin correlations and entanglement of the top-antitop pair near the threshold region.