2015/03/07 by T. A. Trainor, Trainor, Thomas A.
Physics and Astronomy · #FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph) #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions
paper · pdf · doi:10.48550/arxiv.1503.02197
openalex publication_date 2015/03/07 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Fluctuation measurements of event-wise mean transverse momentum ⟨ pt ⟩ for p-p and Pb-Pb collisions at the large hadron collider (LHC) have been reported recently. In that study it was concluded that the strength of "nonstatistical" ⟨ pt ⟩ fluctuations decreases with increasing particle multiplicity nch (or A-A centrality) and is nearly independent of collision energy over a large interval. Among several potential mechanisms for those trends onset of thermalization and collectivity are mentioned. The LHC analysis employed one fluctuation measure selected from several possibilities. An alternative fluctuation measure reveals strong increase of pt fluctuations with nch (or A-A centrality) and collision energy, consistent with previous measurements at the relativistic heavy ion collider (RHIC). The pt fluctuation data for LHC p-p collisions can be described accurately by a two-component (soft+hard) model (TCM) in which the hard component represents dijet production. The data for Pb-Pb collisions are described accurately by a TCM reference for more-peripheral collisions (suggesting transparent collisions), but the data deviate quantitatively from the reference for more-central collisions suggesting modification of jet formation. Overall fluctuation data trends suggest that minimum-bias jets (minijets) dominate pt fluctuations at both the LHC and RHIC.