Photoproduction of $D^{\ast \pm }$ mesons associated with a leading neutron

Abstract

The photoproduction of $D^{\ast \pm }(2010)$ 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, {$x_L>0.2$}, of the incoming proton beam energy and is detected at very small production angles, {${\theta }_n<0.8$ mrad}, an indication of peripheral scattering. The $D^{\ast }$ meson is centrally produced with pseudorapidity {$|\eta |<1.5$}, and has a transverse momentum {$p_T>1.9$ GeV}, which is large compared to the average transverse momentum of the neutron of 0.22 GeV. The ratio of neutron-tagged to inclusive $D^{\ast }$ production is $8.85\pm 0.93(stat.{)}_{-0.61}^{+0.48}(syst.)\%$ 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.

28 pages, 4 figures, 2 tables

References in corpus (6)

• Leading neutron production in $e^{+}p$ collisions at HERA
• Dijet photoproduction at HERA and the structure of the photon
• Measurement of the photon-proton total cross section at a center-of-mass energy of 209 GeV at HERA
• Leading proton production in e^+p collisions at HERA
• Measurement of Dijet Cross Sections in Photoproduction at HERA
• Dijet angular distributions in photoproduction of charm at HERA

Cited by in corpus (13)

• Measurement of Leading Neutron Production in Deep-Inelastic Scattering at HERA
• The Hadronic Final State at HERA
• Leading neutron spectra
• Leading neutron energy and pT distributions in deep inelastic scattering and photoproduction at HERA
• Measurement of open beauty production at HERA in the D* muon final state
• Study of the pion trajectory in the photoproduction of leading neutrons at HERA
• Gluon saturation and Feynman scaling in leading neutron production
• Exclusive processes with a leading neutron in $ep$ collisions
• Determination of neutron fracture functions from a global QCD analysis of leading neutron production at HERA
• High Energy Photoproduction
• Measurement of dijet photoproduction for events with a leading neutron at HERA
• Pion fluctuation in deep inelastic scattering
• Exclusive vector meson production with leading neutrons in a saturation model for the dipole amplitude in mixed space