Inclusive photoproduction of D*(+)/- in ep collisions at HERA has been measured with the ZEUS detector for photon-proton centre of mass energies in the range 115 < W < 280 GeV and photon virtuality Q(2) < 4 GeV2. The cross section sigma(ep) --> D*X integrated over the kinematic region p(D)*(perpendicular to) 3 GeV acid -1.5 < eta(D)* < 1.0 is (10.6 +/- 1.7(stat.)+/-(1.6)(1.3)(syst.)) nb. Differential cross sections as functions of p(D)*(perpendicular to), eta(D)* and W are given. The data are compared with two next-to-leading order perturbative QCD predictions. For a calculation using a massive charm scheme the predicted cross sections are smaller than the measured ones. A recent calculation using a massless charm scheme is in agreement with the data.
Differential cross sections of D*(+/-) photoproduction in ep collisions at HERA
GARFAGNINI, ALBERTO;BRUGNERA, RICCARDO;CARLIN, ROBERTO;STROILI, ROBERTO;
1997
Abstract
Inclusive photoproduction of D*(+)/- in ep collisions at HERA has been measured with the ZEUS detector for photon-proton centre of mass energies in the range 115 < W < 280 GeV and photon virtuality Q(2) < 4 GeV2. The cross section sigma(ep) --> D*X integrated over the kinematic region p(D)*(perpendicular to) 3 GeV acid -1.5 < eta(D)* < 1.0 is (10.6 +/- 1.7(stat.)+/-(1.6)(1.3)(syst.)) nb. Differential cross sections as functions of p(D)*(perpendicular to), eta(D)* and W are given. The data are compared with two next-to-leading order perturbative QCD predictions. For a calculation using a massive charm scheme the predicted cross sections are smaller than the measured ones. A recent calculation using a massless charm scheme is in agreement with the data.Pubblicazioni consigliate
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