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

CMS Collaboration

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21 Citations (Scopus)

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 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.
Original languageEnglish
Article number73
Number of pages42
JournalJournal of High Energy Physics
Volume2016
Issue number4
DOIs
Publication statusPublished - 2016
Externally publishedYes

Keywords

  • Hadron-Hadron scattering (experiments)
  • Top physics

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