Measurement of spin correlation between top and antitop quarks produced in pp¯ collisions at s=1.96 TeV

• Published in: Physics letters. B 2016-06, Vol.757, p.199-206
• Main Authors: Abbott, B., Adams, M., Adams, T., Alton, A., Askew, A., Aushev, Y., Badaud, F., Baldin, B., Bandurin, D.V., Baringer, P., Begalli, M., Bellantoni, L., Bertram, I., Bhatia, S., Blazey, G., Brock, R., Burdin, S., Chen, G., Cihangir, S., Cousinou, M.-C., Demina, R., Diesburg, M., Dubey, A., Eads, M., Ellison, J., Evdokimov, V.N., Ferbel, T., Filthaut, F., Fisk, H.E., Fortner, M., Fuess, S., Garcia-Bellido, A., García-González, J.A., Gerber, C.E., Greder, S., Grenier, G., Grünendahl, S., Haley, J., Harel, A., Hauptman, J.M., Hegab, H., Hensel, C., Hirosky, R., Hoang, T., Jayasinghe, A., Jeong, M.S., Jonsson, P., Juste, A., Katsanos, I., Kharchilava, A., Kozelov, A.V., Kumar, A., Kupco, A., Lammers, S., Lee, S.W., Li, D., Lincoln, D., Linnemann, J., Liu, Y., Lopes de Sa, R., Luna-Garcia, R., Malik, S., McCarthy, R., Miconi, F., Nagy, E., Nguyen, H.T., Partridge, R., Penning, B., Popov, A.V., Prewitt, M., Qian, J., Quadt, A., Quinn, B., Ratoff, P.N., Santos, A.S., Schott, M., Shabalina, E., Shaw, S., Sonnenschein, L., Soustruznik, K., Titov, M., Tokmenin, V.V., Tsai, Y.-T., Uzunyan, S., van Leeuwen, W.M., Varelas, N., Vesterinen, M., Vokac, P., Wang, M.H.L.S., Wilson, G.W., Wobisch, M., Wood, D.R., Wyatt, T.R., Xie, Y., Yasuda, T., Yatsunenko, Y.A., Ye, Z., Youn, S.W., Zieminska, D., Zivkovic, L.
• Format: Article
• Language: English
• Subjects: PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
• ISSN: 0370-2693; 1873-2445
• DOI: 10.1016/j.physletb.2016.03.053

We present a measurement of the correlation between the spins of t and t¯ quarks produced in proton–antiproton collisions at the Tevatron Collider at a center-of-mass energy of 1.96 TeV. We apply a matrix element technique to dilepton and single-lepton+jets final states in data accumulated with the D0 detector that correspond to an integrated luminosity of 9.7 fb−1. The measured value of the correlation coefficient in the off-diagonal basis, Ooff=0.89±0.22(stat+syst), is in agreement with the standard model prediction, and represents evidence for a top–antitop quark spin correlation difference from zero at a level of 4.2 standard deviations.