2002/12/31 by Geoffrey T. Bodwin, Eric Braaten, Jungil Lee · 60 citations
Physics and Astronomy · #Annihilation #Atomic physics #Energy (signal processing) #Fragmentation (computing) #High-Energy Particle Collisions Research #Nuclear physics #Parity (physics) #Particle physics #Particle physics theoretical and experimental studies #Photon #Physics #Production (economics) #Quantum Chromodynamics and Particle Interactions #Quantum mechanics #hep-ph
paper · pdf · doi:10.1103/physrevd.67.054023
published in Physical review. D. Particles, fields, gravitation, and cosmology/Physical review. D. Particles and fields 67(5) (American Physical Society) · 15 pages, 2 figures, 3 tables, revised to correct errors in original version, Erratum to Phys. Rev. D article included as a separate file
openalex publication_date 2003/03/28 · arxiv created 2005/10/25 · arxiv updated 2014/11/17 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We calculate the contributions from QED processes involving two virtual photons to the cross sections for e+e^\ensuremath- annihilation into two charmonium states with the same C parity. Generically, the cross sections are three orders of magnitude smaller than those for charmonia with opposite C parity because they are suppressed by a factor of \ensuremathα2/\ensuremathαs2. However, if both charmonia have quantum numbers JPC=1^\ensuremath-\ensuremath-, then there is a contribution to the cross section that involves the fragmentation of each photon into a charmonium. The fragmentation contribution is enhanced by powers of Ebeam/mc, the ratio of the beam energy to the charm-quark mass, and this enhancement can compensate for the suppression factor that is associated with the coupling constants. In particular, the predicted cross section for J/\ensuremathψ+J/\ensuremathψ at the B factories is larger than that for J/\ensuremathψ+\ensuremathηc.