2014/09/30 by Şener Özönder, Sener Ozonder
Physics and Astronomy · #Azimuth #Color-glass condensate #Gluon #Hadron #High-Energy Particle Collisions Research #Large Hadron Collider #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Rapidity #Saturation (graph theory) #hep-ph #nucl-th
paper · pdf · doi:10.1103/physrevd.91.034005
published as Phys. Rev. D 91, 034005 (2015) · Only the published version includes the latest changes (more explanations and references)
openalex publication_date 2015/02/05 · arxiv created 2015/02/11 · arxiv updated 2015/02/12 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We calculate the triple- and quadruple-gluon inclusive distributions with arbitrary rapidity and azimuthal angle dependence in the gluon saturation regime by using glasma diagrams. Also, we predict higher-dimensional ridges in triple- and quadruple-hadron correlations for p--p and p--Pb collisions at LHC, which have yet to be measured. In p--p and p--Pb collisions at the top LHC energies, gluon saturation is expected to occur since smaller Bjorken-x values are being probed. Glasma diagrams, which are enhanced at small-x, include gluon saturation effects, and they are used for calculating the long-range rapidity correlations (``ridges'') and vn moments of the azimuthal distribution of detected hadrons. The glasma description reproduces the systematics of the data on both p--p and p--Pb ridges. As an alternative, relativistic hydrodynamics has also been applied to these small systems quite successfully. With the triple- and quadruple-gluon azimuthal correlations, this work aims to set the stage by going beyond the double-gluon azimuthal correlations in order to settle unambiguously the origin of ``collectivity'' in p--p and p--Pb collisions. We derive the triple- and quadruple-gluon azimuthal correlation functions in terms of unintegrated gluon distributions at arbitrary rapidities and azimuthal angles of produced gluons. Then, unintegrated gluon distributions from the running coupling Balitsky-Kovchegov evolution equation are used to calculate the triple- and quadruple-gluon correlations for various parameters of gluon momenta, initial scale for small-x evolution and beam energy.