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

Autori
Khachatryan, Vardan ; ... ; Morović, Srećko ; Ferenček, Dinko ; Đurić, Senka ; Godinović, Nikola ; Lelas, Damir ; Puljak, Ivica ; Ribeiro Cipriano, Pedro Miguel ; Antunović, Željko ; Kovač, Marko ; Brigljević, Vuko ; Kadija, Krešo ; Luetić, Jelena ; Mićanović, Saša ; Sudić, Lucija ; ... ; Woods, Nate

Izvornik
Journal of High Energy Physics (1029-8479) 2016 (2016), 4; 073-1

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
High energy physics ; Experimental particle physics ; LHC ; CMS ; Standard Model

Sažetak
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.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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