Search for anomalous couplings in top decay at hadron colliders

S. Tsuno, I. Nakano, R. Tanaka, Y. Sumino

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9 Citations (Scopus)


We present a quantitative study on sensitivities to the top-decay anomalous couplings, taking into account realistic experimental conditions expected at Tevatron and LHC. A double angular distribution of W and charged lepton in the top-decay is analyzed, using tt̄ events in the leptons+jets channel. In order to improve sensitivities to the anomalous couplings, we apply two techniques: (i) We use a likelihood fitting method for full kinematical reconstruction of each top event. (ii) We develop a new effective spin reconstruction method for leptonically-decayed top quarks; this method does not require spin information of the antitop side. For simplicity, we neglect couplings of right-handed bottom quark as well as CP violating couplings. The 95% C.L. estimated bound on a ratio of anomalous couplings reads -0.81<f2/f1<-0.70, -0.12<f2/f1<0.14 using 1000 reconstructed top events at Tevatron, while -0.74<f2/f1<-0.72, -0.01<f2/f1<0.01 is expected with 100 k reconstructed top events at LHC, where only statistical errors are taken into account. A two-fold ambiguity in the allowed range remains when the number of events exceeds a few hundred.

Original languageEnglish
Article number054011
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number5
Publication statusPublished - 2006

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Physics and Astronomy (miscellaneous)


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