Baryon Form Factors: Where do we stand?
23. Apr - 27. Apr 2018
Physikzentrum Bad Honnef
Dr. A. Dbeyssi, GSI/Helmholtz-Inst. Mainz • Prof. E. Tomasi-Gustafsson, U Paris/FRA • Dr. S. Pacetti, Perugia/ITA
Electromagnetic form factors are basic quantities containing the dynamical information of the hadron structure. Although form factors constitute one of the main fields of research on hadron physics since many years, recent technical developments and discoveries modified essentially our understanding of the nucleon and opened new questions. The surprising results obtained by the JLab-GEp Collaboration, using the Akhiezer-Rekalo polarization method, have shown a decreasing of the ratio of electric to magnetic form factor of the proton, contrary to what currently assumed. Electron-positron colliders, using the initial state radiation have given precise results in the time-like region, showing the presence of regular structures. Questions on the reaction mechanism and on the size and dependence of radiative corrections on the kinematical variables are open. New, sophisticated tools start to be available, as dedicated Monte Carlo and a web site for data basis. Active developments of methods and phenomenology aim to a global understanding in time-like and space-like regions. Gathering experimentalists and theoreticians seems timely for a critical discussion of the recent results and reanalysis of data obtained at DESY, VEPPII, JLab, BABAR and BESIII, before the future measurements such as the upgraded JLab experiments, and at the future facility FAIR. The aim of the this seminar is to:
Clarify past and recent experimental results and critically compare different analysis and interpretations.
Discuss the present data from two photon exchange experiments and the applied corrections.
Deepen the understanding of the reaction amplitudes for the crossed elementary processes involving electrons and protons, through a unified analysis in space and time-like regions.
The organizers invite young researchers to apply and to contribute to the presentation or poster sessions by using the application form.