Constraining gluon poles

Abstract

In this letter, we revise the QED gauge invariance for the hadron tensor of Drell-Yan type processes with the transversely polarized hadron. We perform our analysis within the Feynman gauge for gluons and make a comparison with the results obtained within the light-cone gauge. We demonstrate that QED gauge invariance leads, first, to the need of a non-standard diagram and, second, to the absence of gluon poles in the correlators $⟨\bar{\psi }{\gamma }_{\perp }{A}^{+}\psi ⟩$ related traditionally to $dT(x,x)/dx$. As a result, these terms disappear from the final QED gauge invariant hadron tensor. We also verify the absence of such poles by analysing the corresponding light-cone Dirac algebra.

5 pages, 2 figures. The improved version. Accepted for publication in PLB

References in corpus (3)

• A Unified Picture for Single Transverse-Spin Asymmetries in Hard Processes
• The RHIC SPIN Program: Achievements and Future Opportunities
• New contributions to gluon poles in direct photon production

Cited by in corpus (6)

• Drell-Yan hadron tensor: contour gauge and gluon propagator
• Drell-Yan-like processes and duality
• Gluon poles and photon distribution amplitudes in Drell-Yan-like processes
• Angular distributions in pion-nucleon Drell-Yan process
• Study of Spin through Gluon Poles
• Factorization theorem, gluon poles and new contributions in semi-inclusive processes