Periodic interference structures in the time-like proton form factor

Abstract

An intriguing and elusive feature of the timelike hadron form factor is the possible presence of an imaginary part associated to rescattering processes. We find evidence of that in the recent and precise data on the proton timelike form factor measured by the BABAR collaboration. By plotting these data as a function of the 3-momentum of the relative motion of the final proton and antiproton, a systematic sinusoidal modulation is highlighted in the near-threshold region. Our analysis attributes this pattern to rescattering processes at a relative distance of 0.7-1.5 fm between the centers of the forming hadrons. This distance implies a large fraction of inelastic processes in $\bar{p}p$ interactions, and a large imaginary part in the related $e^{+}{e}^{-}\to \bar{p}p$ reaction because of unitarity.

5 pages 3 figures - Discussion modified. To appear in Phys Rev Letters

References in corpus (4)

• Light-Front Dynamics and AdS/QCD Correspondence: The Pion Form Factor in the Space- and Time-Like Regions
• Dispersion analysis of the nucleon form factors including meson continua
• Electroweak structure of the nucleon, meson cloud and light-cone wavefunctions
• Measuring the deviation from the Rutherford formula