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Measurement of top quark polarisation in t-channel single top quark production

CMS Collaboration; Khachatryan, V.; Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragicevic, M.; Erö, J.; Flechl, M.; Friedl, M.; Frühwirth, R.; Ghete, V.M.; Hartl, C.; Hörmann, N.; Hrubec, J.; Jeitler, M.; Knünz, V.; König, A.; ... mehr

Abstract (englisch):
A 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. © 2016, The Author(s).

Zugehörige Institution(en) am KIT Institut für Experimentelle Kernphysik (IEKP)
Publikationstyp Zeitschriftenaufsatz
Jahr 2016
Sprache Englisch
Identifikator DOI: 10.1007/JHEP04(2016)073
ISSN: 1126-6708
URN: urn:nbn:de:swb:90-549048
KITopen ID: 1000054904
Erschienen in Journal of High Energy Physics
Band 2016
Heft 4
Seiten 73
Bemerkung zur Veröffentlichung Gefördert durch SCOAP3
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