6533b86cfe1ef96bd12c7d69
RESEARCH PRODUCT
Observation of Spin Correlation in t(t)over-bar Events from pp Collisions at root s=7 TeV Using the ATLAS Detector
Atlas CollaborationVasiliki MitsouJuan A. Fuster VerdúAntonio Ferrer SoriaMaría Victoria Castillo GiménezSusana Cabrera UrbánCarmen García GarcíaEmilio Higón RodríguezSalvador Martí GarcíaEduardo Ros MartínezSantiago González De La HozJosé Salt CairolsJuan Antonio Valls FerrerMohammed KaciLuca FioriniYesenia Hernández JiménezCarlos Lacasta LlácerMiguel Villaplana Pérezsubject
Col·lisions (Física nuclear)High Energy Physics::ExperimentPartícules (Física nuclear)Detectors de radiaciódescription
A measurement of spin correlation in t (t) over bar production is reported using data collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 2.1 fb(-1). Candidate events are selected in the dilepton topology with large missing transverse energy and at least two jets. The difference in azimuthal angle between the two charged leptons in the laboratory frame is used to extract the correlation between the top and antitop quark spins. In the helicity basis the measured degree of correlation corresponds to A(helicity) = 0.40(-0.08)(+0.09), in agreement with the next-to-leading-order standard model prediction. The hypothesis of zero spin correlation is excluded at 5.1 standard deviations.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2012-01-01 |