Diffractive W production at hadron colliders as a test of colour singlet exchange mechanisms

TL;DR

This paper compares soft colour exchange models and pomeron exchange models for diffractive W production at hadron colliders, showing they produce similar results for certain observables and highlighting the potential to distinguish models through differential distributions.

Contribution

It provides a detailed analysis of soft colour exchange models at LHC energies, demonstrating their similarities to pomeron models and exploring their sensitivity to hadronisation and colour reconnection effects.

Findings

Soft colour exchange models mimic pomeron models for leading protons and W production.

W charge asymmetry vanishes in both models at high energies.

Differential distributions can discriminate between different colour reconnection models.

Abstract

We revisit diffractive and exclusive W production at hadron colliders in different models for soft colour exchanges. The process pp to p[WX]p, and in particular a W charge asymmetry, has been suggested as a way to discriminate diffractive processes as being due to pomeron exchange in Regge phenomenology or QCD-based colour reconnection models. Our detailed analysis of the latter models at LHC energies shows, however, that they give similar results as pomeron models for very leading protons and central W production, including a vanishing W charge asymmetry. We demonstrate that soft colour exchange models provide a continuous transition from diffractive to inelastic processes and thereby include the intrinsic asymmetry of inelastic interactions while being at the same time sensitive to the underlying hadronisation models. Such sensitivity also concerns the differential distributions in proton momentum and W transverse momentum which opens possibilities to discriminate between different colour reconnection models.