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 19.7fb−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.

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

SOLA, VALENTINA;AMAPANE, Nicola Carlo;ARGIRO', Stefano;BELLAN, Riccardo;COSTA, Marco;COVARELLI, Roberto;MIGLIORE, Ernesto;MONACO, Vincenzo;OBERTINO, Maria Margherita;PACHER, LUCA;PELLICCIONI, Mario;PINNA ANGIONI, GIAN LUCA;RAVERA, FABIO;ROMERO, Alessandra;SACCHI, Roberto;SOLANO, Ada Maria;
2016-01-01

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 19.7fb−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
2016
4
1
42
http://link.springer.com/journal/13130
Hadron-Hadron scattering (experiments); Top physics; Nuclear and High Energy Physics
The CMS collaboration, Null; Khachatryan, V.; Sirunyan, A.M.; Tumasyan, A.; Adam, W.; Asilar, E.; Bergauer, T.; Brandstetter, J.; Brondolin, E.; Dragi...espandi
File in questo prodotto:
File Dimensione Formato  
JHEP04_2016_073.pdf

Accesso aperto

Tipo di file: PDF EDITORIALE
Dimensione 1.05 MB
Formato Adobe PDF
1.05 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1639574
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 31
  • ???jsp.display-item.citation.isi??? 25
social impact