Research Papers in Physics and Astronomy


Date of this Version



PHYSICAL REVIEW D 95, 011101(R) (2017)


© 2017 American Physical Society

DOI: 10.1103/PhysRevD.95.011101


We present a measurement of top quark polarization in tt pair production in pp collisions at [?] = 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 final states 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 tt production plane. This is the first measurement of top quark polarization at the Tevatron using lepton + jet final states and the first measurement of the transverse polarization in tt production. The observed distributions are consistent with standard model predictions of nearly no polarization.