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

Abstract : 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 inverse-femtobarns. 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.
Type de document :
Article dans une revue
Journal of High Energy Physics, Springer Verlag (Germany), 2016, 04, pp.073. 〈10.1007/JHEP04(2016)073〉

http://hal.in2p3.fr/in2p3-01226175
Contributeur : Sylvie Flores <>
Soumis le : lundi 9 novembre 2015 - 07:34:04
Dernière modification le : jeudi 10 mai 2018 - 02:00:33

### Citation

V. Khachatryan, M. Besançon, F. Couderc, M. Dejardin, D. Denegri, et al.. Measurement of top quark polarisation in t-channel single top quark production. Journal of High Energy Physics, Springer Verlag (Germany), 2016, 04, pp.073. 〈10.1007/JHEP04(2016)073〉. 〈in2p3-01226175〉

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