par Adloff, Catherine;Clerbaux, Barbara 
;Collard, Caroline ;de Wolf, Els;Favart, Laurent ;Heremans, R.;Janssen, Xavier ;Johnson, Denis;Marage, Pierre ;Roosen, Robert;Van Mechelen, Pierre; [et al.]
Référence Physics letters. Section B, 483, 1-3, page (23-35)
Publication Publié, 2000-06
;Collard, Caroline ;de Wolf, Els;Favart, Laurent ;Heremans, R.;Janssen, Xavier ;Johnson, Denis;Marage, Pierre ;Roosen, Robert;Van Mechelen, Pierre; [et al.]Référence Physics letters. Section B, 483, 1-3, page (23-35)
Publication Publié, 2000-06
Article révisé par les pairs
| Résumé : | Cross sections for elastic photoproduction of J/ψ and Υ mesons are presented. For J/ψ mesons the dependence on the photon-proton centre-of-mass energy W(γp) is analysed in an extended range with respect to previous measurements of 26 ≤ W(γp) ≤ 285 GeV. The measured energy dependence is parameterized as σ(γp) α W(γp)/δ with δ = 0.83 ± 0.07. The differential cross section dσ/dt for J/ψ mesons is derived, its dependence on W(γp) and on t is analysed and the effective trajectory (in terms of Regge theory) is determined to be α(t) = (1.27 ± 0.05) + (0.08 ± 0.17) · t/GeV2. Models based on perturbative QCD and on pomeron exchange are compared to the data. (C) 2000 Elsevier Science B.V. |
