Color-neutral heavy particle production in nucleus-nucleus collisions in the quasi-classical approximation

Abstract

We use a diagrammatic approach to study color-neutral heavy particle production in nucleus-nucleus collisions in a quasi-classical approximation without small-$x$ evolution. In order to treat the two nuclei symmetrically, we use the Coulomb gauge which gives the appropriate light cone gauge for each nucleus. The resulting cross section is factorized into a product of two Weizsäcker-Williams gluon distributions of the two nuclei when the transverse momentum of the produced scalar particle is around the saturation momentum. We confirm our results in covariant gauge where the transverse momentum broadening of hard gluons can be described as a diffusion process. The transverse momentum factorization manifests itself in light cone gauge but not so clearly in covariant gauge.

25 pages, 29 figures, v2: extended and improved discussion, a new appendix and references added

References in corpus (4)

• Universality of Unintegrated Gluon Distributions at small x
• High energy factorization in nucleus-nucleus collisions
• Direct Probes of Linearly Polarized Gluons inside Unpolarized Hadrons
• The classical field created in early stages of high energy nucleus-nucleus collisions

Cited by in corpus (6)

• Sudakov Resummation in Small-x Saturation Formalism
• Probing Gluon Saturation through Dihadron Correlations at an Electron-Ion Collider
• Azimuthal asymmetries for quark pair production in pA collisions
• Transverse single spin asymmetry in direct photon production in polarized pA collisions
• Classical Gluon Production Amplitude for Nucleus-Nucleus Collisions: First Saturation Correction in the Projectile
• Next-to-Leading Order correction to inclusive particle spectra in the Color Glass Condensate framework