Non-collinearity in high energy processes
arXiv:0806.1134 · doi:10.1007/s12043-009-0007-x
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.
9 pages Invited talk at the Xth Workshop on High Energy Physics Phenomenology (WHEPP X), Chennai (India), January 2-13, 2008
References in corpus (8)
- Matches and mismatches in the descriptions of semi-inclusive processes at low and high transverse momentum
- The Construction of Gauge-Links in Arbitrary Hard Processes
- Non-universality of transverse momentum dependent parton distribution functions
- Spectral analysis of gluonic pole matrix elements for fragmentation
- The Sivers single-spin asymmetry in photon-jet production
- Single-Transverse Spin Asymmetry in Dijet Correlations at Hadron Colliders
- Spin asymmetries in jet-hyperon production at LHC
- T-odd effects in photon-jet production at the Tevatron