TY - JOUR

T1 - Normalization of QCD effects on O(mt2) electroweak corrections

AU - Smith, Brian H.

AU - Voloshin, M. B.

N1 - Copyright:
Copyright 2015 Elsevier B.V., All rights reserved.

PY - 1995

Y1 - 1995

N2 - We point out that, contrary to some recent claims, there is no intrinsic long-distance uncertainty in the perturbative calculation of the QCD effects in the tt̄ and tb̄ loops giving the electroweak corrections proportional to mt2. If these corrections are expressed in terms of the "on-shell" mass mt, the only ambiguity arising is that associated with the definition of the "on-shell" mass of a quark. The latter is entirely eliminated if the result is expressed in terms of mt defined at short distances. Applying the Brodsky-Lepage-Mackenzie criterion for determining the natural scale for normalization of αs, we find that using the "on-shell" mass makes this scale numerically small in units of mt. Specifically, we find that by this criterion the first QCD correction to the O(mt2) terms is determined by αsMS̄(0.15mt). Naturally, a full calculation of three-loop graphs is needed to completely quantify the scale.

AB - We point out that, contrary to some recent claims, there is no intrinsic long-distance uncertainty in the perturbative calculation of the QCD effects in the tt̄ and tb̄ loops giving the electroweak corrections proportional to mt2. If these corrections are expressed in terms of the "on-shell" mass mt, the only ambiguity arising is that associated with the definition of the "on-shell" mass of a quark. The latter is entirely eliminated if the result is expressed in terms of mt defined at short distances. Applying the Brodsky-Lepage-Mackenzie criterion for determining the natural scale for normalization of αs, we find that using the "on-shell" mass makes this scale numerically small in units of mt. Specifically, we find that by this criterion the first QCD correction to the O(mt2) terms is determined by αsMS̄(0.15mt). Naturally, a full calculation of three-loop graphs is needed to completely quantify the scale.

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U2 - 10.1103/PhysRevD.51.5251

DO - 10.1103/PhysRevD.51.5251

M3 - Article

AN - SCOPUS:0000960378

VL - 51

SP - 5251

EP - 5255

JO - Physical review D: Particles and fields

JF - Physical review D: Particles and fields

SN - 1550-7998

IS - 9

ER -