The photoproduction of D*Â±(2010) mesons associated with a leading neutron has been observed with the ZEUS detector in ep collisions at HERA using an integrated luminosity of 80 pb-1. The neutron carries a large fraction, xL>0.2, of the incoming proton beam energy and is detected at very small production angles, Î¸n< 0.8 mrad, an indication of peripheral scattering. The D* meson is centrally produced with pseudorapidity Î·<1.5, and has a transverse momentum pT>1.9 GeV, which is large compared to the average transverse momentum of the neutron of 0.22 GeV. The ratio of neutron-tagged to inclusive D* production is 8.85Â±0.93(stat.) +0.48-0.61(syst.)% in the photon-proton center-of-mass energy range 130<W<280 GeV. The data suggest that the presence of a hard scale enhances the fraction of events with a leading neutron in the final state. Â© 2004 Elsevier B.V. All rights reserved.
|Titolo:||Photoproduction of D*± mesons associated with a leading neutron|
|Data di pubblicazione:||2004|
|Appare nelle tipologie:||1.1.1 Articolo su rivista con DOI|