Speaker
Description
We present a measurement of top quark polarization in ttbar pair production in ppbar collisions at $\sqrt(s)=1.96$ TeV using data corresponding to 9.7 fb$^{-1}$ of integrated luminosity recorded with the D0 detector at the Fermilab Tevatron Collider. We consider the final state containing a lepton and at least three jets. The polarization is measured through the distribution of lepton angles along three axes: the beam axis, the helicity axis, and the transverse axis normal to the ttbar production plane. This is the first measurement of top quark polarization at Tevatron using lepton+jet final state and the first measurement of the transverse polarization in ttbar production. The observed distributions are consistent with standard model predictions of nearly no polarization.
