Abstract
We introduce a notion of position-space cuts of eikonal diagrams, the set of diagrams appearing in the perturbative expansion of the correlator of a set of straight semi-infinite Wilson lines. The cuts are applied directly to the position-space representation of any such diagramand compute its imaginary part to the leading order in the dimensional regulator. Our cutting prescription thus defines a position-space analog of the standard momentum-space Cutkosky rules. Unlike momentum-space cuts which put internal lines on shell, position-space cuts constrain a number of the gauge bosons exchanged between the energetic partons to be lightlike, leading to a vanishing and a non-vanishing imaginary part for space-and timelike kinematics, respectively.
| Original language | English |
|---|---|
| Article number | 181602 |
| Pages (from-to) | 1-5 |
| Journal | Physical Review Letters |
| Volume | 114 |
| Issue number | 18 |
| DOIs | |
| Publication status | Published - 8 May 2015 |
Funding
We thank S. Abreu, S. Caron-Huot, E. Gardi, J. Henn, P. Hoyer, L. Magnea, G. Sterman, I. Stewart, W. Vleeshouwers, A. Waelkens, C. White, and especially G. Korchemsky for useful discussions. We are grateful for the hospitality of the Higgs Centre of the University of Edinburgh. K. J. L. is grateful for the hospitality of the Institute for Advanced Study in Princeton and the Institut de Physique Theorique, CEA Saclay, where part of this work was carried out. The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. 627521. This work was supported by the Foundation for Fundamental Research of Matter (FOM), program 104 "Theoretical Particle Physics in the Era of the LHC" and by the Research Executive Agency (REA) of the European Union under the Grant Agreement No. PITN-GA-2010-264564 (LHCPhenoNet).
Keywords
- LOOP AMPLITUDES
- CROSS-SECTIONS
- RENORMALIZATION
- EXPONENTIATION
- UNITARITY
- ORDER
- QCD