1.
Phys Rev Lett
; 90(9): 092001, 2003 Mar 07.
Artigo
em Inglês
| MEDLINE
| ID: mdl-12689214
RESUMO
Exclusive proton-antiproton annihilation into two photons at large s ( approximately 10 GeV2) and /t/,/u/ approximately s can be described by a generalized parton picture analogous to the "soft mechanism" in wide-angle real Compton scattering. The two photons are emitted in the annihilation of a single fast quark and antiquark. The matrix element describing the transition of the pp system to a qq pair can be related to the timelike proton elastic form factors as well as to the quark/antiquark distributions measured in inclusive deep-inelastic scattering. The reaction could be studied with the proposed 1.5-15 GeV high-luminosity antiproton storage ring (HESR) at GSI.