Mutual boosting of the saturation scales in colliding nuclei
arXiv:1007.1913 · doi:10.1016/j.physletb.2011.02.018
Abstract
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 Q_{sA}^2, in AA compared with pA collisions.
arXiv comment12 pages, 4 figures. Extended version to be published in Phys. Lett. B
References in corpus (36)
- Parton distributions for the LHC
- Computing Quark and Gluon Distribution Functions for Very Large Nuclei
- Operator expansion for high-energy scattering
- Gluon Distribution Functions for Very Large Nuclei at Small Transverse Momentum
- Small-x F_2 Structure Function of a Nucleus Including Multiple Pomeron Exchanges
- Radiative energy loss and -broadening of high energy partons in nuclei
- Green's Functions in the Color Field of a Large Nucleus
- Hadron production in nuclear collisions at RHIC and high density QCD
- Uncertainties on alpha_S in global PDF analyses and implications for predicted hadronic cross sections
- Manifestations of high density QCD in the first RHIC data
- A Modification of the Saturation Model: DGLAP evolution
- Saturation Physics and Deuteron--Gold Collisions at RHIC
- Production of gluons in the classical field model for heavy ion collisions
- Phobos results on charged particle multiplicity and pseudorapidity distributions in Au+Au, Cu+Cu, d+Au, and p+p collisions at ultra-relativistic energies
- Color Glass Condensate at the LHC: hadron multiplicities in , and collisions
- Nonperturbative Effects in Gluon Radiation and Photoproduction of Quark Pairs
- The onset of classical QCD dynamics in relativistic heavy ion collisions
- Nuclear enhancement of universal dynamics of high parton densities
- QCD Saturation and Deuteron-Nucleus Collisions
- Gluon production in the Color Glass Condensate model of collisions of ultrarelativistic finite nuclei
- High energy factorization in nucleus-nucleus collisions
- J/psi Production in sqrt (s_NN)= 200 GeV Cu+Cu Collisions
- Numerical analysis of the Balitsky-Kovchegov equation with running coupling: dependence of the saturation scale on nuclear size and rapidity
- Saturation and parton level Cronin effect: enhancement vs suppression of gluon production in p-A and A-A collisions
- Nonlinear QCD Evolution: Saturation without Unitarization
- High energy factorization in nucleus-nucleus collisions II - Multigluon correlations
- Photoproduction of Charmonia and Total Charmonium-Proton Cross Sections
- High energy factorization in nucleus-nucleus collisions III. Long range rapidity correlations
- Interaction of small size wave packet with hadron target
- Broadening of Transverse Momentum of Partons Propagating through a Medium
- System Size, Energy and Centrality Dependence of Pseudorapidity Distributions of Charged Particles in Relativistic Heavy Ion Collisions
- Evidences for two scales in hadrons
- Colour Screening, Quark Propagation in Nuclear Matter and the Broadening of the Momentum Distribution of Drell-Yan Pairs
- Measuring the saturation scale in nuclei
- Gluon Saturation Effects in Relativistic U+U Collisions
- Charmonium Suppression in Heavy Ion Collisions by Prompt Gluons
Cited by in corpus (10)
- A Fixed-Target Programme at the LHC: Physics Case and Projected Performances for Heavy-Ion, Hadron, Spin and Astroparticle Studies
- J/Psi in high-multiplicity pp collisions: lessons from pA
- Nuclear suppression of J/Psi: from RHIC to the LHC
- Suppression vs enhancement of heavy quarkonia in pA collisions
- Heavy quarkonium in saturated environment of high-multiplicity pp collisions
- Survival of charmonia in a hot environment
- Puzzles of J/Psi production off nuclei
- Strangeness production in high-multiplicity events
- Universal Centrality Dependence of Particle Multiplicities in Heavy-Ion Collisions
- Multiplicity dependence of production at forward rapidity in pp collisions at = 13 TeV