Measurements of Spin Correlation in ttbar Events at D0
  Two recent measurements by the D0 Collaboration of spin correlation in ttbar production using 5.4 fb^-1 of Tevatron ppbar collider data are presented. Both rely on the dilepton final state of ttbar. One measurement relies on full reconstruction of the top quark kinematics, and the other makes use of leading-order matrix elements to characterize the kinematics. The latter measurement is the first ever to have sufficient analyzing power to exclude the no-correlation hypothesis. 
Kenneth Bloom (for the D0 Collaboration)
hep-ex