Measurement of associated production of vector bosons and top quark-antiquark pairs in pp collisions at root s=7 TeV

Chatrchyan S., Khachatryan V., Sirunyan A. M., Tumasyan A., Adam W., Aguilo E., ...More

PHYSICAL REVIEW LETTERS, vol.110, no.17, 2013 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 110 Issue: 17
  • Publication Date: 2013
  • Doi Number: 10.1103/physrevlett.110.172002
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Middle East Technical University Affiliated: Yes


The first measurement of vector-boson production associated with a top quark-antiquark pair in proton-proton collisions at root s = 7 TeV is presented. The results are based on a data set corresponding to an integrated luminosity of 5.0 fb(-1), recorded by the CMS detector at the LHC in 2011. The measurement is performed in two independent channels through a trilepton analysis of t (t) over barZ events and a same-sign dilepton analysis of t (t) over barV (V = W or Z) events. In the trilepton channel a direct measurement of the t (t) over barZ cross section sigma(t (t) over barZ) = 0.28(-0.11)(+0.14) (stat)(-0.03)(+0.06) (syst) pb is obtained. In the dilepton channel a measurement of the t (t) over barV cross section yields sigma(t (t) over barV) = 0.43(-0.15)(+0.17) (stat)(-0.07)(+0.09) (syst) pb. These measurements have a significance, respectively, of 3.3 and 3.0 standard deviations from the background hypotheses and are compatible, within uncertainties, with the corresponding next-to-leading order predictions of 0.137(-0.016)(+0.012) and 0.306(-0.053)(+0.031) pb. DOI: 10.1103/PhysRevLett.110.172002