Geometrical scaling and the dependence of the average transverse momentum on the multiplicity and energy for the ALICE experiment

2014/07/31 by Larry McLerran, Michał Praszałowicz, Michal Praszalowicz · 30 citations
Mathematics · Physics and Astronomy · #Exponent #Geometry #High-Energy Particle Collisions Research #Impact parameter #Mathematics #Multiplicity (mathematics) #Nuclear physics #Particle physics #Particle physics theoretical and experimental studies #Physics #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #Scaling #Scattering #Transverse plane #hep-ph #nucl-th

paper · pdf · doi:10.1016/j.physletb.2014.12.046

published in Physics Letters B 741, 246-251 (Elsevier BV) · 15 pages, 7 figures, in v2 one figure and one reference added, v3: version accepted in Phys. Lett. B., some modifications, references added

arxiv created 2014/12/22 · openalex publication_date 2014/12/24 · arxiv updated 2015/10/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

We review the recent ALICE data on charged particle multiplicity in p–p collisions, and show that it exhibits Geometrical Scaling (GS) with energy dependence given with characteristic exponent λ=0.22. Next, starting from the GS hypothesis and using results of the Color Glass Condensate effective theory, we calculate 〈pT〉 as a function Nch including dependence on the scattering energy W. We show that 〈pT〉 both in p–p and p–Pb collisions scales in terms of scaling variable (W/W0)λ/(2+λ)Nch/S⊥ where S⊥ is multiplicity-dependent interaction area in the transverse plane. Furthermore, we discuss how the behavior of the interaction radius R at large multiplicities affects the mean pT dependence on Nch, and make a prediction that 〈pT〉 at high multiplicity should reach an energy-independent limit.

Citations

• Wilson renormalization group for lowxphysics: Towards the high density regime
• How protons shatter colored glass
• Traveling wave fronts and the transition to saturation
• The BFKL equation from the Wilson renormalization group
• Manifestations of high density QCD in the first RHIC data
• Geometric Scaling as Traveling Waves
• Glittering Glasmas

Cited by

• Transverse momentum fluctuation under the Tsallis distribution at high energies
• Saturation and Geometrical Scaling: from Deep Inelastic ep Scattering to Heavy Ion Collisions
• Geometrical scaling for energies available at the BNL Relativistic Heavy Ion Collider to those at the CERN Large Hadron Collider
• Momentum distribution and correlation for a free scalar field in the Tsallis nonextensive statistics based on density operator

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• System size and energy dependence of the mean transverse momentum fluctuations at the LHC