Production of electroweak gauge bosons at forward rapidities in the color - dipole $S$ - matrix framework

Abstract

The cross-section for the production of an electroweak gauge boson ($G=W^{\pm },Z^0,\gamma$) at forward rapidities in $pp$ collisions is derived within the color - dipole $S$ - matrix framework. We present the full expressions for the differential cross-section of the $qp\to GX$ process in the impact parameter and transverse momentum spaces, considering the longitudinal and transverse polarizations of the gauge boson. The particular cases associated with the Drell - Yan process and real photon production are discussed. We demonstrate that the final formulae are expressed in terms of the dipole - proton cross-section or the unintegrated gluon distribution, and can be used to estimate the impact of the saturation effects in the gauge boson production at the LHC and future colliders.

Comments: 18 pages, 2 figures, 1 table