Model independent constraints among the Wtb, Zbb̄, and Ztt̄ couplings

Edmond L. Berger, Qing Hong Cao, Ian Low

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


Using an effective Lagrangian approach, we perform a model-independent analysis of the interactions among electroweak gauge bosons and the third generation quarks, i.e. the Wtb, Ztt̄, and Zbb̄ couplings. After one imposes the known experimental constraint on the ZbLbL coupling, we show that the electroweak SU(2)L×U(1)Y symmetry of the standard model specifies the pattern of deviations of the ZtLtL and WtLbL couplings, independent of underlying new physics scenarios. We study implications of the predicted pattern with data on the single top quark and Ztt̄ associated production processes at the Large Hadron Collider. Such an analysis could in principle allow for a determination of the Wtb coupling without prior knowledge of |Vtb|, which is otherwise difficult to achieve.

Original languageEnglish (US)
Article number074020
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number7
StatePublished - Oct 20 2009

ASJC Scopus subject areas

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


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