Measurement of the W-boson helicity in top-quark decays from t(t)over-bar production in lepton plus jets events in pp collisions at root s=7 TeV


Chatrchyan S., Khachatryan V., Sirunyan A. M., Tumasyan A., Adam W., Bergauer T., ...Daha Fazla

JOURNAL OF HIGH ENERGY PHYSICS, sa.10, 2013 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: Sayı: 10
  • Basım Tarihi: 2013
  • Doi Numarası: 10.1007/jhep10(2013)167
  • Dergi Adı: JOURNAL OF HIGH ENERGY PHYSICS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Anahtar Kelimeler: Hadron-Hadron Scattering, Top physics, PARTON DISTRIBUTIONS, FRACTIONS, LHC
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

The W-boson helicity fractions in top-quark decays are measured with t (t) over bar events in the lepton+jets final state, using proton-proton collisions at a centre-of-mass energy of 7 TeV, collected in 2011 with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 5.0 fb(-1). The measured fractions of longitudinal, left-, and right-handed helicity are F-0 = 0.682 +/- 0.030 (stat.) +/- 0.033 (syst.), F-L = 0.310 +/- 0.022 (stat.) +/- 0.022 (syst.), and F-R = 0.008 +/- 0.012 (stat.) +/- 0.014 (syst.), consistent with the standard model predictions. The measured fractions are used to probe the existence of anomalous Wtb couplings. Exclusion limits on the real components of the anomalous couplings g(L), g(R) are also derived.