Decisive test of color coherence in proton-nucleus collisions at the LHC

Abstract

Proton-nucleus collisions (p+A) at LHC energies provide a rigorous test of the Color Glass Condensate (CGC), a model proposed to describe the high energy limit of Quantum Chromodynamics. In the CGC the average multiplicity of charged particles at midrapidity in p+A collisions depends logarithmically on the number of participants, $N_{part}$. In contrast, the Wounded Nucleon Model (WNM) of independent nucleon-nucleon scatterings, verified at RHIC energies, predicts that multiplicity in p+A depends linearly on $N_{part}$. We argue that for the first time, the dependence of mean multiplicity on $N_{part}$ in p+A collisions at LHC energies can single out a model of particle production, thus offering a stringent test of the CGC and the WNM. Based on this observation we propose a novel experimental test of color coherence in p+A collisions.

5 pages, 4 figures; version accepted for publication, minor changes

References in corpus (5)

• Initial state geometry and the role of hydrodynamics in proton-proton, proton-nucleus and deuteron-nucleus collisions
• Collective dynamics of the high-energy proton-nucleus collisions
• CGC predictions for p+Pb collisions at the LHC
• Wounded quarks and diquarks in high energy collisions
• Average transverse momentum of hadrons in proton-nucleus collisions in the wounded nucleon model

Cited by in corpus (9)

• QCD and strongly coupled gauge theories: challenges and perspectives
• Elliptic and triangular flow in p+Pb and peripheral Pb+Pb collisions from parton scatterings
• Long-range azimuthal correlations in proton-proton and proton-nucleus collisions from the incoherent scattering of partons
• Diffractive and non-diffractive wounded nucleons and final states in pA collisions
• The rapidity dependence of the average transverse momentum in p+Pb collisions at the LHC: the Color Glass Condensate versus hydrodynamics
• Centrality dependence of high energy jets in p+Pb collisions at the LHC
• p-Pb collisions at 5.02 TeV in the Parton-Hadron-String-Dynamics transport approach
• Multi-particle eccentricities in collisions dominated by fluctuations
• Multiplicity and Pseudorapidity distributions of charged particles in asymmetric and deformed nuclear collisions in a Wounded Quark Model