2010/07/31 by B. Z. Kopeliovich, H. J. Pirner, I. K. Potashnikova +2
Physics and Astronomy · #Asymmetry #Boosting (machine learning) #DGLAP #Gluon #High-Energy Particle Collisions Research #Nuclear physics #Nucleon #Nucleus #Particle physics #Particle physics theoretical and experimental studies #Parton #Physics #Projectile #Quantum Chromodynamics and Particle Interactions #Quantum electrodynamics #Quantum mechanics #Quark #Rest frame #Saturation (graph theory) #hep-ph #nucl-ex #nucl-th
paper · pdf · doi:10.1016/j.physletb.2011.02.018
published as Phys.Lett.B697:333-338,2011 · 12 pages, 4 figures. Extended version to be published in Phys. Lett. B
arxiv created 2011/02/04 · openalex publication_date 2011/02/10 · arxiv updated 2011/03/03 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Saturation of small-x gluons in a nucleus, which has the form of transverse momentum broadening of projectile gluons in pA collisions in the nuclear rest frame, leads to a modification of the parton distribution functions in the beam compared with pp collisions. The DGLAP driven gluon distribution turns out to be suppressed at large x, but significantly enhanced at x≪1. This is a high twist effect. In the case of nucleus–nucleus collisions all participating nucleons on both sides get enriched in gluon density at small x, which leads to a further boosting of the saturation scale. We derive reciprocity equations for the saturation scales corresponding to a collision of two nuclei. The solution of these equations for central collisions of two heavy nuclei demonstrate a significant, up to several times, enhancement of QsA2, in AA compared with pA collisions.