A description of the ratio between electric and magnetic proton form factors by using space-like, time-like data and dispersion relations

R. Baldini; C. Bini; P. Gauzzi; M. Mirazita; M. Negrini; S. Pacetti

doi:10.1140/epjc/s2006-02499-4

EPJ

A description of the ratio between electric and magnetic proton form factors by using space-like, time-like data and dispersion relations

R. Baldini¹^,2, C. Bini³, P. Gauzzi³, M. Mirazita², M. Negrini⁴ and S. Pacetti²^*

¹ Centro Studi e Ricerche Enrico Fermi, Roma, Italy
² Laboratori Nazionali di Frascati dell’INFN, Frascati, Italy
³ Università “La Sapienza” e Sezione INFN, Roma, Italy
⁴ Università di Ferrara e Sezione INFN, Ferrara, Italy

Received: 8 July 2005
Published online: 31 March 2006

Abstract

We use the available information on the ratio between the electric and magnetic proton form factors coming from recently published space-like data and from the few available time-like data. We apply a dispersive procedure on these data to evaluate the behavior of this ratio, as a complex function, for all values of q².