2008/05/30 by M. J. Tannenbaum, Tannenbaum, M. J.
Physics and Astronomy · #FOS: Physical sciences #High-Energy Particle Collisions Research #Nuclear Experiment (nucl-ex) #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #nucl-ex
paper · pdf · doi:10.48550/arxiv.0806.0040
4 pages, 4 figures, to appear in the proceedings of XLIII Rencontres de Moriond, QCD and High Energy Interactions, La Thuile, Italy, Mar 8-15, 2008. v2 corrects title misspelling in listing
openalex publication_date 2008/05/30 · arxiv created 2008/06/03 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Hard-scattering of point-like constituents (or partons) in p-p collisions was discovered at the CERN-ISR in 1972 by measurements utilizing inclusive single or pairs of hadrons with large transverse momentum (pT). It was generally assumed following a seminal paper by Feynman, Field and Fox (FFF) (and much discussed in a talk that I gave at the 1979 Rencontres de Moriond) that ``everything you wanted to know about hard-scattering and jets'' could be measured by these methods. Recently, we found in PHENIX that the pTa distribution of away side hadrons from a single particle trigger [with pTt] which is a leading fragment of the trigger jet, could not be used to measure the fragmentation function of the away jet as originally claimed by FFF. A new formula was derived which both exhibits scaling in the variable xE∼ pTa/pTt (a hot topic in 1979) and relates xE, ∼ the ratio of the transverse momenta of the measured particles, to xh=pTa/pTt, the ratio of the transverse momenta of the away-side to trigger-side jets. Tests of the validity of the formula and applications to Au+Au central collisions at RHIC (where jets can not be reconstructed) are discussed.