Published March 13, 2012 | Version Published
Journal Article Open

Measurement of the charge asymmetry in top-quark pair production in proton–proton collisions at √s = 7 TeV

Abstract

The difference in angular distributions between top quarks and antiquarks, commonly referred to as the charge asymmetry, is measured in pp collisions at the LHC with the CMS experiment. The data sample corresponds to an integrated luminosity of 1.09 fb^(−1) at a centre-of-mass energy of 7 TeV. Top-quark pairs are selected in the final state with an electron or muon and four or more jets. At least one jet is identified as originating from b-quark hadronization. The charge asymmetry is measured in two variables, one based on the pseudorapidities (η) of the top quarks and the other on their rapidities (y). The results A^η_C = −0.017 ± 0.032 (stat.) ^(+0.025)_(−0.036) (syst.) and A^y_C = −0.013 ± 0.028 (stat.) ^(+0.029)_(−0.031) (syst.) are consistent within uncertainties with the standard-model predictions.

Additional Information

© 2012 CERN. Published by Elsevier B.V. This article is published Open Access at sciencedirect.com. It is distributed under the terms of the Creative Commons Attribution License 3.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are credited. Received 21 December 2011. Revised 31 January 2012. Accepted 31 January 2012. Available online 3 February 2012. Editor: M. Doser. We thank Johann H. Kühn and German Rodrigo for very fruitful discussions, and we wish to congratulate our colleagues in the CERN accelerator departments for the excellent performance of the LHC machine. We thank the technical and administrative staff at CERN and other CMS institutes, and acknowledge support from: FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, MEC, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLP-FAI (Mexico); MSI (New Zealand); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST, MAE and RFBR (Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA). Individuals have received support from the Marie-Curie programme and the European Research Council (European Union); the Leventis Foundation; the A.P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation à la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); and the Council of Science and Industrial Research, India.

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Additional details

Identifiers

Eprint ID
31342
Resolver ID
CaltechAUTHORS:20120508-094806197

Funding

FMSR (Austria)
FNRS and FWO (Belgium)
CNPq (Brazil)
CAPES (Brazil)
FAPERJ (Brazil)
FAPESP (Brazil)
MES (Bulgaria)
CERN
CAS (China)
MOST and NSFC (China)
COLCIENCIAS (Colombia)
MSES (Croatia)
RPF (Cyprus)
Academy of Sciences and NICPB (Estonia)
Academy of Finland
CEA and CNRS/IN2P3 (France)
BMBF (Germany)
DFG and HGF (Germany)
GSRT (Greece)
OTKA and NKTH (Hungary)
DAE and DST (India)
IPM (Iran)
SFI (Ireland)
INFN (Italy)
NRF and WCU (Korea)
LAS (Lithuania)
CINVESTAV (Mexico)
CONACyT (Mexico)
SEP and UASLP-FAI (Mexico)
MSI (New Zealand)
PAEC (Pakistan)
SCSR (Poland)
FCT (Portugal)
JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan)
MST (Russia)
MAE and RFBR (Russia)
MSTD (Serbia)
MICINN and CPAN (Spain)
Swiss Funding Agencies (Switzerland)
NSC (Taipei)
TUBITAK and TAEK (Turkey)
STFC (United Kingdom)
Department of Energy (DOE)
NSF
Marie-Curie programme and the European Research Council (European Union)
Leventis Foundation
A.P. Sloan Foundation
Alexander von Humboldt Foundation
Belgian Federal Science Policy Office
Fonds pour la Formation à la Recherche dans l'índustrie et dans l'Ágriculture (FRIA-Belgium)
Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium)
Council of Science and Industrial Research, India

Dates

Created
2012-05-08
Created from EPrint's datestamp field
Updated
2021-11-09
Created from EPrint's last_modified field

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