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Breakdown of QCD coherence ?

A. Kyrieleis·J. R. Forshaw·M. H. Seymour
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Abstract

We reconsider the calculation of a non-global QCD observable and find the possible breakdown of QCD coherence. This breakdown arises as a result of wide angle soft gluon emission developing a sensitivity to emission at small angles and it leads to the appearance of super-leading logarithms. We use the `gaps between jets' cross-section as a concrete example and illustrate that the new logarithms are intimately connected with the presence of Coulomb gluon contributions. Numerical estimates of their potential phenomenological significance are presented.

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A. Kyrieleis, J. R. Forshaw, M. H. Seymour. 2006-12-16. Breakdown of QCD coherence ?. https://arxiv.org/abs/hep-ph/0612202

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