Measurement of spin correlation in ttbar production using a matrix element approach

0367818 - FZÚ 2013 RIV US eng J - Journal Article
Abazov, V. M. - Abbott, B. - Acharya, B.S. - Kupčo, Alexander - Lokajíček, Miloš … Total 421 authors
Measurement of spin correlation in ttbar production using a matrix element approach.
Physical Review Letters. Roč. 107, č. 3 (2011), "032001-1"-"032001-7". ISSN 0031-9007. E-ISSN 1079-7114
R&D Projects: GA MŠMT LA08047
Institutional research plan: CEZ:AV0Z10100502
Keywords : D0 * Tevatron * dilepton * anti-p p * spin
Subject RIV: BF - Elementary Particles and High Energy Physics
Impact factor: 7.370, year: 2011

We determine the fraction of t (t) over bar events with spin correlation, assuming that the spin of the top quark is either correlated with the spin of the top antiquark as predicted by the standard model or is uncorrelated. For the first time we use a matrix-element-based approach to study t (t) over bar spin correlation. We use t (t) over bar -> W(+)bW(-)(b) over bar -> l(+)nu bl(-)(nu) over bar(b) over bar final states produced in p (p) over bar collisions at a center- of- mass energy root s = 1: 96 TeV, where l denotes an electron or a 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 result agrees with the standard model prediction. We exclude the hypothesis that the spins of the t (t) over bar are uncorrelated at the 97.7% C.L.
Permanent Link: http://hdl.handle.net/11104/0202365