Top-quark mass and isospin breaking in the dynamical symmetry-breaking scenario

T. Asaka, Y. Shobuda, Y. Sumino

Research output: Contribution to journalArticlepeer-review


We consider a scenario where the top-quark mass is generated dynamically, and study the implications of the present experimental values for [Formula presented] and the [Formula presented] parameter. We assume a technicolorlike scenario for inducing the [Formula presented] mass and an effective four-Fermi operator for inducing the top-quark mass. We also assume that only this four-Fermi operator is relevant at low energy. Then we estimate in detail the strength [Formula presented] and the intrinsic mass scale [Formula presented] of the four-Fermi operator. A unitarity bound is used to quantify the strength of [Formula presented]. We find that [Formula presented] and that [Formula presented] is of the order of [Formula presented] TeV or less. Namely the four-Fermi operator cannot be treated as "pointlike" around the electroweak scale. Furthermore we estimate the contribution of the four-Fermi operator to the [Formula presented] parameter. We find that the QCD correction to the top-quark mass function reduces the contribution to the [Formula presented] parameter by about 40%. By comparing the results with the present experimental bound, we obtain another upper bound on [Formula presented] which is typically in the several to 10 TeV region.

Original languageEnglish
Pages (from-to)5698-5704
Number of pages7
JournalPhysical Review D - Particles, Fields, Gravitation and Cosmology
Issue number9
Publication statusPublished - 1996

ASJC Scopus subject areas

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

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