1993/05/13 by Adam F. Falk, Michael Luke, Martin J. Savage +1 · 2 citations
Physics and Astronomy · #High-Energy Particle Collisions Research #Particle physics theoretical and experimental studies #Quantum Chromodynamics and Particle Interactions #hep-ph
paper · pdf · doi:10.1016/0370-2693(93)90986-r
published as Phys.Lett. B312 (1993) 486-490 · 8 pages, 1 figure included, uses harvmac.tex and epsf.tex, UCSD/PTH 93-06, CALT-68-1864, SLAC-PUB-6175
arxiv created 1993/05/13 · openalex publication_date 1993/08/01 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We calculate the polarisation of ψ's and Υ's produced by the fragmentation of heavy quarks. We find that fragmentation to transversely aligned quarkonium is slightly enhanced relative to longitudinally polarised. This net alignment corresponds to a ∼ 5% asymmetry in the angular distribution of leptons produced in the subsequent decay of the quarkonium. We point out that the leading gluon contribution to ψ and Υ production arises from the evolution of the charm quark fragmentation function, rather than from direct gluon fragmentation.