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The view of the Priorat Palace in Gatchina

Experimental and theoretical aspects of the proton form factors
St.Petersburg,   Gatchina,
Petersburg Nuclear Physics Institute (PNPI),   July 9 - 11, 2012

The form factors are important characteristics of the proton structure related to the spatial distributions of the proton charge and magnetization. In polarization experiments at JLAB, the startling discrepancy has been observed in the ratio of the electric to magnetic form factors for elastic electron scattering from the proton. A possible explanation for the discrepancy is that multi-photon processes are playing a significant role at higher momentum transfers. As far as strong interactions are involved in these processes they cannot be reproduced theoretically from general principles and thus both experimental and theoretical investigations of multi-photon processes must be performed. There are three experiments presently in progress to study possible contributions from these effects: the OLYMPUS experiment at DORIS, DESY in Hamburg, the experiment at VEPP3 storage ring in Novosibirsk, and EG5 CLAS experiment at JLab.

We hope that Scientific Program of this symposium offers a good opportunity to physicists and students to exchange information and report on their investigations including apparatus details, Monte Carlo analyses and evaluation of systematic uncertainties, theoretical models of multi-photon processes, possible other experiments aimed at the nucleon form factor problem, etc. For the first time, a similar discussion with focus on theoretical aspects of the multi-photon processes was organized at MIT in July 30, 2011 (

It is planned that the symposium will take place in the PNPI from 9 to 11 July with an excursion day (Social Program) on Wednesday 11. The symposium dinner is planned for Monday 9. All other information on symposium is specified in labeled sections. We would like to ask symposium participants please not to postpone your registration and in particular (if needed) visa processing.

Deadline for registration is June 5, 2012

Program Committee:

Reinhard Beck,   Bonn University
Stanislav Belostotski (Co-chair),   PNPI
Dmitri Diakonov,   PNPI
Douglas Hasell,   MIT
Nikolai Kivel,   Helmholtz Institute Mainz
Michael Kohl,   Hampton University and JLAB

Lev Lipatov,   PNPI
Richard Milner (Co-chair),   MIT
Michael Ryskin,   PNPI
Uwe Schneekloth,   DESY
Dmitri Toporkov,   Budker INP Novosibirsk
Alexey Vorobyov,   PNPI

Local organizing committee (PNPI):

Stanislav Belostotski (Chair)
Alexander Beresnev
Zoya Gaditskaya
Vladimir Gugneshov
Lyudmila Ivanova
Anton Izotov
Anatoly Krivshich
Oleg Miklukho (Co-chair)

Yuriy Naryshkin (Co-chair)
Natalia Nikitina
Larisa Obrant
Svetlana Udalova
Denis Veretennikov
Pavel Yakimov
Rimma Zheronkina

Organized by:

St. Petersburg Nuclear Physics Institute  (view PNPI).

Contact persons:

Stanislav Belostotski

Phone:      +7(813)7130087 (in Russia)
Mobile:     +79119753932
Phone:      +49(40)89983648   (in Germany )

Yuri Naryshkin

Phone:      +7(813)7130087   (in Russia)
Mobile:     +79117966270
Phone:      +49(40)89981608   (in Germany )

Fax:      +7(813)7137196   (PNPI, International office)