Decoupling heavy particles simultaneously

R. J. Crewther; S. D. Bass; F. M. Steffens; A. W. Thomas

doi:10.1016/j.nuclphysbps.2004.12.024

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arXiv · hep-ph/0601244

Decoupling heavy particles simultaneously

R. J. Crewther·S. D. Bass·F. M. Steffens·A. W. Thomas

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Abstract

The renormalization group is extended to cases where several heavy particles are decoupled at the same time. This involves large logarithms which are scale-invariant and so cannot be eliminated by a change of renormalization scheme. A set of scale-invariant running couplings, one for each heavy particle, is constructed without reference to intermediate thresholds. The entire heavy-quark correction to the axial charge of the weak neutral current is derived to next-to-leading order, and checked in leading order by evaluating diagrams explicitly. The mechanism for cancelling contributions from the top and bottom quarks in the equal-mass limit is surprisingly non-trivial.

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R. J. Crewther, S. D. Bass, F. M. Steffens, A. W. Thomas. 2006-01-30. Decoupling heavy particles simultaneously. https://doi.org/10.1016/j.nuclphysbps.2004.12.024

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