1. Recent results on diffractive and forward physics at HERA
- Author
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Yuji, Yamazaki, H1 Collaboration, and ZEUS Collaboration
- Subjects
Quark ,Particle physics ,Photon ,Meson ,direct production [photon] ,density [parton] ,QC1-999 ,electroproduction [vector meson] ,diffraction ,Parton ,low [transverse momentum] ,01 natural sciences ,7. Clean energy ,Nuclear physics ,deep inelastic scattering [lepton p] ,Recoil ,factorization ,0103 physical sciences ,recoil ,Neutron ,ddc:530 ,Vector meson ,010306 general physics ,Nuclear Experiment ,Physics ,010308 nuclear & particles physics ,electroproduction [psi(3685)] ,electroproduction [heavy quark] ,High Energy Physics::Phenomenology ,HERA ,wave function [charmonium] ,electroproduction [J/psi(3100)] ,DESY HERA Stor ,High Energy Physics::Experiment ,photoproduction [rho(770)] ,ratio [cross section] - Abstract
Recent studies on diffractive processes in ep scattering at HERA are reviewed. Heavy quark production in diffractive processes was studied by tagging a D * meson in diffractive DIS events. The cross section for events with a prompt photon in the final state was also measured. The data are well reproduced by models using diffractive parton densities determined from inclusive diffractive DIS cross sections. Two studies were also made on exclusive vector meson production. The cross-section ratio σψ( (2S ))/σ (ψ (1S )), which reflects the difference in transverse shape of the charmonium wave functions, are compared to various models. Moreover, the diffractive ρ 0 photoproduction with a forward neutron, which has two vertices with small-pT recoil, were measured to study factorisation properties. The data show some indication of re-scattering.
- Published
- 2017
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