Measurement of spin correlation in tt‾ production using dilepton final states

Abstract

We measure the correlation between the spin of the top quark and the spin of the anti-top quark in tt‾→W⁺bW^-b‾→l⁺νbl^-νb‾ final states produced in pp‾ collisions at a center of mass energy s=1.96 TeV, where l is an electron or muon. The data correspond to an integrated luminosity of 5.4 fb^-1 and were collected with the D0 detector at the Fermilab Tevatron collider. The correlation is extracted from the angles of the two leptons in the t‾ and t rest frames, yielding a correlation strength C=0.10^+0.45_-0.45, in agreement with the NLO QCD prediction within two standard deviations, but also in agreement with the no correlation hypothesis.