par Aid, S;Barth, Marie ;Coremans, Ghislaine ;Botterweck, F.;Clerbaux, Barbara ;de Wolf, Els;Evrard, E.;Favart, Laurent ; [et al.]
Référence Nuclear physics. B, 463, 1, page (3-29)
Publication Publié, 1996-03
Référence Nuclear physics. B, 463, 1, page (3-29)
Publication Publié, 1996-03
Article révisé par les pairs
Résumé : | The cross section for the elastic photoproduction of ρ0 mesons (γp → ρ0p) has been measured with the H1 detector at HERA for two average photon-proton centre-of-mass energies of 55 and 187 GeV. The lower energy point was measured by observing directly the ρ0 decay giving a cross section of 9.1 ± 0.9 (stat.) ± 2.5 (syst.) μb. The logarithmic slope parameter of the differential cross section, dσ/dt, is found to be 10.9 ± 2.4 (stat.) ± 1.1 (syst.) GeV-2. The ρ0 decay polar angular distribution is found to be consistent with s-channel helicity conservation. The higher energy cross section was determined from analysis of the lower part of the hadronic invariant mass spectrum of diffractive photoproduction and found to be 13.6 ± 0.8 (stat.) ± 2.4 (syst.) μb. |