TY - JOUR

T1 - Top-quark mass and isospin breaking in the dynamical symmetry-breaking scenario

AU - Asaka, T.

AU - Shobuda, Y.

AU - Sumino, Y.

N1 - Copyright:
Copyright 2017 Elsevier B.V., All rights reserved.

PY - 1996

Y1 - 1996

N2 - 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.

AB - 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.

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U2 - 10.1103/PhysRevD.54.5698

DO - 10.1103/PhysRevD.54.5698

M3 - Article

AN - SCOPUS:3042950560

VL - 54

SP - 5698

EP - 5704

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

SN - 1550-7998

IS - 9

ER -