CMS CollaborationKarapınar, Güler2017-09-062017-09-062016Khachatryan, V., Sirunyan, A.M., Tumasyan, A., Adam, W., Asilar, E., Bergauer, T.,...CMS Collaboration (2016). Measurement of top quark polarisation in t-channel single top quark production. Journal of High Energy Physics, 2016(4). doi:10.1007/JHEP04(2016)0731029-8479http://doi.org/10.1007/JHEP04(2016)073https://hdl.handle.net/11147/6200A first measurement of the top quark spin asymmetry, sensitive to the top quark polarisation, in t-channel single top quark production is presented. It is based on a sample of pp collisions at a centre-of-mass energy of 8 TeV corresponding to an integrated luminosity of 19.7 fb−1. A high-purity sample of t-channel single top quark events with an isolated muon is selected. Signal and background components are estimated using a fit to data. A differential cross section measurement, corrected for detector effects, of an angular observable sensitive to the top quark polarisation is performed. The differential distribution is used to extract a top quark spin asymmetry of 0.26 ± 0.03(stat) ± 0.10(syst), which is compatible with a p-value of 4.6% with the standard model prediction of 0.44.eninfo:eu-repo/semantics/openAccessLarge Hadron Collider (LHC)Compact Muon SolenoidArticle2-s2.0-8496389381910.1007/JHEP04(2016)07310.1007/JHEP04(2016)073