Momentum flow correlations from event shapes: Factorized soft gluons and soft-collinear effective theory

By Christopher Lee, G. Sterman. 2006

159 citations recorded by the source corpus.

The distributions of two-jet event shapes contain information on hadronization in QCD. Near the two-jet limit, these distributions can be described by convolutions of nonperturbative event shape functions with the same distributions calculated in resummed perturbation theory. The shape functions, in turn, are determined by correlations of momentum flow operators with each other and with lightlike Wilson lines, which describe the coupling of soft, wide-angle radiation to jets. We observe that leading power corrections to the mean values of event shapes are determined by the correlation of a single momentum flow operator with the relevant Wilson lines. This generalizes arguments for the universality of leading power corrections based on the low-scale behavior of the running coupling or resummation. We also show how a study of the angularity event shapes can provide information on correlations involving multiple momentum flow operators, giving a window to the system of QCD dynamics that underlies the variety of event shape functions. In deriving these results, we review, develop and compare factorization techniques in conventional perturbative QCD and soft-collinear effective theory (SCET). We give special emphasis to the elimination of double counting of momentum regions in these two formalisms.

Subfields: Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/442d00efb9b85def2bd283e390deb2900ac65a20

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In Nuclear and High Energy Physics

1. A. Larkoski
2. Jesse Thaler
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Citations in the corpus

• Factorization at the LHC: From parton distribution functions to initial state jets (2010, methodology): “In practice when calculating matrix elements, this is implemented using zero-bin subtractions [140] or alternatively by dividing out matrix elements of Wilson lines [120, 134].”
• Factorization at the LHC: From PDFs to Initial State Jets (Ph.D. thesis) (2009, methodology): “In practice when calculating matrix elements, this is implemented using zero-bin subtractions [140] or alternatively by dividing out matrix elements of Wilson lines [120, 134].”
• Jet shapes with the broadening axis (2014, background): “For β < 1, the leading non-perturbative power correction will be controlled by the collinear modes, not the soft modes as it is for β > 1 observables like thrust [54].”
• A formalism for the systematic treatment of rapidity logarithms in Quantum Field Theory (2012, background): “It has been shown that in SCETI this “zero bin” subtraction [17–19] is often equivalent to dividing by matrix element of Wilson lines in non-SCET perturbative QCD factorization formulae [20], which can often be identified with the inverse of the soft-function in the factorization theorem.”
• Introduction to Soft-Collinear Effective Theory (2014, background): “Lee and Sterman were able to show that the same parameter governs the leading non-perturbative corrections for all values α < 1 [233] and recently this result was extended to the broadening α = 1 [67].”
• Jet shapes and jet algorithms in SCET (2010, methodology): “[17, 29, 41] for the case of hemisphere jet algorithms that these corrections in turn induce corrections to the angularity τa of order λ 2(2−a), which, for τa ∼ λ2, are subleading for a < 1.”
• The quark beam function at NNLL (2010, methodology): “(This is easy to see by formulating the zero-bin subtraction as a field redefinition [18] analogous to the soft one but with Wilson lines in a different light-cone direction.”