On hard exclusive reactions in the time-like region

Abstract

The proton form factor, two-photon annihilations into $p\bar{p}$ as well as exclusive charmonium decays are critically examined. It will be argued that the standard perturbative QCD analysis of these reactions fails, i.e. the need for additional contributions can convincingly be demonstrated. Possible dynamical mechanisms such as colour-octet admixtures to the charmonium states or diquarks inside baryons, will be discussed and compared to the data.

Invited talk presented at the Fourth Biennal Conference on Low-Energy Antiproton Physics, LEAP96, Dinkelsbühl (August 1996); 8 pages, LaTeX, 4 PS-figures; uses 'espcrc2.sty' and 'psfig.sty'

References in corpus (6)

• Rigorous QCD Analysis of Inclusive Annihilation and Production of Heavy Quarkonium
• Meson-Photon Transition Form Factors
• On Exclusive Reactions in the Time-Like Region
• Octet-Baryon Form Factors in the Diquark Model
• An update on ${\chi }_c$ Decays: Perturbative QCD versus Data
• On the Nucleon Distribution Amplitude: The Heterotic Solution

Cited by in corpus (3)

• Form Factors and QCD in Spacelike and Timelike Region
• Theory of hadron decay into baryon-antibaryon final state
• Theory of time-like baryon form factors near thresholds