Measurement of the photon electroproduction cross section at JLab with the goal performing a Rosenbluth separation of the DVCS contribution

Abstract

An elementary particle is a particle whose substructure is unknown, thus it is unknown whether it is composed of other particles. Historically, the atom constituent particles (electrons, protons and neutrons) were all regarded as elementary particles. However, with the discovery of the magnetic moment of the proton, it became clear that the proton did not belong to this category. With further experimentation, more evidence was found that protons and neutrons, as well as all hadrons, were composed of other particles, and had an internal structure. The first evidence for quarks as real constituent elements of hadrons was obtained in late 1967, when the first of a long series of experiments on highly inelastic electron scattering was started at the two mile accelerator at the Stanford Linear Accelerator Center (SLAC).