Bulg. J. Phys. vol.44 no.S1 (2017), pp. 003-015

Highlights in the Hadron Electromagnetic Structure

E. Tomasi-Gustafsson1, S. Pacetti2, A. Bianconi3
1IRFU, CEA, Université Paris-Saclay, 91191 Gif-sur-Yvette Cedex, France
2Dipartimento di Fisica e Geologia, and INFN Sezione di Perugia, 06123 Perugia, Italy
3Dipartimento di Ingegneria dell'Informazione, Università di Brescia and Istituto Nazionale di Fisica Nucleare, via A. Bassi 6, 27100 Pavia, It
Abstract. In frame of a general view of proton electromagnetic form factors, two recent findings related to reanalyses of data are presented. Recent experiments in the scattering and in the annihilation region provided us with more precise data and/or extending the kinematical region, allowing a deeper analysis and a common view of these fundamental quantities. We will discuss two issues: the discrepancy between the form factors extracted from unpolarized and polarized $ep$ elastic scattering experiments, in connection with the commonly used dipole parametrization; peculiar oscillations in e+e- → p̅p (γ) annihilation cross section, that become periodical when plotted as a function of the 3-momentum of the relative motion of the final proton and antiproton, after subtraction of a smooth function.

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