Measurement of the proton form factor at low momentum transfer.

Abstract

Electron scattering experiments on the proton were carried out in a range of momentum transfers squared of 0.025 (Fermi -2) to be 0.65 (Fermi -2). Polyethylene was used as target material and the proton data were normalized against carbon electron scattering data taken at higher momentum transfer. The relative proton data obtained in this manner do not fit the generally accepted form factor curve. Possible reasons for the deviations in view of recent suggestions about the existence of a proton halo are offered. However, it is not possible at the present stage of accuracy to make any definite statement except that the data are not inconsistent with the existence of a proton halo.