Forward trijet production in proton-nucleus collisions

TL;DR

This paper calculates the cross-section for forward trijet production in proton-nucleus collisions using light-cone wave functions and hybrid factorization, focusing on the quark channel with successive splittings.

Contribution

It introduces a detailed computation of the three-parton component of the quark light-cone wave function for the first time, relevant for next-to-leading order jet production corrections.

Findings

Provides a formalism for three-parton production at forward rapidities.

Derives the scattering of on-shell three-parton states off a nuclear shockwave.

Offers a new ingredient for higher-order QCD calculations in proton-nucleus collisions.

Abstract

Using the formalism of the light-cone wave function in perturbative QCD together with the hybrid factorization, we compute the cross-section for three particle production at forward rapidities in proton-nucleus collisions. We focus on the quark channel, in which the three produced partons -- a quark accompanied by a gluon pair, or two quarks plus one antiquark -- are all generated via two successive splittings starting with a quark that was originally collinear with the proton. The three partons are put on-shell by their scattering off the nuclear target, described as a Lorentz-contracted "shockwave". The three-parton component of the quark light-cone wave function that we compute on this occasion is also an ingredient for other interesting calculations, like the next-to-leading order correction to the cross-section for the production of a pair of jets.