TL;DR
This paper explores how intrinsic transverse momenta and gauge links in QCD affect high energy scattering processes, revealing process-dependent effects like single spin asymmetries and challenging the universality of distribution functions.
Contribution
It provides a detailed analysis of gauge link effects on transverse momentum dependent correlators and their impact on observable asymmetries in high energy QCD processes.
Findings
Gauge links cause process-dependent asymmetries.
Time reversal odd phenomena arise from gauge link structures.
Universality of distribution functions is challenged by color flow dependence.
Abstract
We discuss the treatment of intrinsic transverse momenta in high energy scattering processes. Within the field theoretical framework of QCD the process is described in terms of correlators containing quark and gluon fields. The correlators, parameterized in terms of distribution and fragmentation functions, contain matrix elements of nonlocal field configurations requiring a careful treatment to assure color gauge invariance. It leads to nontrivial gauge links connecting the parton fields. For the transverse momentum dependent correlators the gauge links give rise to time reversal odd phenomena, showing up as single spin and azimuthal asymmetries. The gauge links, arising from multi-gluon initial and final state interactions, depend on the color flow in the process, challenging universality.
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.