Total Cross Sections with Virtual Photons
نویسنده
چکیده
A model for total cross sections with virtual photons is presented, in particular γp and γγ cross sections are considered. Our approach is based on an existing model for photoproduction, which subdivides the total cross section into three distinct event classes: direct, VMD and anomalous [1]. In the region of large photon virtualities, the Deep Inelastic Scattering processes (up to O(αs) corrections) are obtained. Hence, the model provides a smooth transition between the two regions. By the breakdown into different event classes, a complete picture of all event properties is the ultimate goal. To appear in the Proceedings of the LEP2 Workshop on Monte Carlo generators [email protected]
منابع مشابه
Total Cross Sections and Event Properties from Real to Virtual Photons
A model for total cross sections with virtual photons is presented. In particular γp and γγ cross sections are considered. Our approach extends on a model for photoproduction, where the total cross section is subdivided into three distinct event classes: direct, VMD and anomalous. With increasing photon virtuality, the latter two decrease in importance. Instead Deep Inelastic Scattering dominat...
متن کاملConsequences of t-channel unitarity for the interaction of real and virtual photons at high energies
We analyze the consequences of t-channel unitarity for photon cross sections and show what assumptions are necessary to allow for the existence of new singularities at Q = 0 for the γp and γγ total cross sections. For virtual photons, such singularities can in general be present, but we show that, apart from the perturbative singularity associated with γ∗γ∗ → qq̄, no new ingredient is needed to ...
متن کاملTotal Cross Section Measurements in γp and γp at HERA
Measurements of the total cross section for real and virtual photons on protons at center-of-mass energies in the range from 20 GeV to 270 GeV with photon virtualities up to 5000 GeV are presented. For real photons this cross section can be described by Regge-motivated models while for virtual photons perturbative QCD can be applied. The measurements of the two HERA collider experiments ZEUS an...
متن کاملar X iv : h ep - e x / 99 09 02 3 v 1 1 4 Se p 19 99 Experimental Results on Two - Photon Physics from LEP
This review covers selected results from the LEP experiments on the structure of quasi-real and virtual photons. The topics discussed are the total hadronic cross-section for photon-photon scattering, hadron production, jet cross-sections, heavy quark production for photon-photon scattering, photon structure functions, and crosssections for the exchange of two virtual photons.
متن کاملTotal Photonic and Hadronic Cross - sections 1
We discuss total cross-sections within the context of the QCD calculable mini-jet model, highlighting its successes and failures. In particular we show its description of γγ → hadrons and compare it with OPAL and L3 data. We extrapolate this result to γ p total cross-sections and propose a phenomenological ansätz for virtual photon cross-sections. We point out that the good agreement with data ...
متن کامل