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arXiv · 1406.4570

Renormalization group-induced phenomena of top pairs from four-quark effective operators

Abstract

We study the renormalization group(RG) evolution of four-quark operators that contribute to the top pair production. In particular, we focus on the cases in which certain observables are \emph{first} induced from the one-loop RG while being absent at tree-level. From the operator mixing pattern, we classify all such RG-induced phenomena and underlying models that can induce them. We then calculate the full one-loop QCD RG evolution as the leading estimator of the effects and address the question of which RG-induced phenomena have largest and observable effects. The answer is related to the color structure of QCD. The studied topics include the RG-induction of top asymmetries, polarizations and polarization mixings as well as issues arising at this order. The RG-induction of top asymmetries is further compared with the generation of asymmetries from QCD and QED at one-loop order. We finally discuss the validity of using the RG as the proxy of one-loop effects on the top pair production. As an aside, we clarify the often-studied relations between top pair observables.

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Sunghoon Jung, P. Ko, Yeo Woong Yoon, Chaehyun Yu. 2014-10-07. Renormalization group-induced phenomena of top pairs from four-quark effective operators. https://doi.org/10.1007/jhep08(2014)120

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