EXPERIMENTS ON THE STRUCTURE OF AN INDIVIDUAL ELEMENTARY PARTICLE

Research begun in the early 1970s on geonium is reviewed. Geonium is a man-made atom, created at liquid-helium temperature in ultrahigh vacuum from an individual electron in magnetic and electric trapping fields. For this atom the electron gyromagnetic ratio g=2. 000 000 000 110(60) has been measured in microwave spectroscopy experiments after subtraction of quantum electrodynamics shifts. The g-gDirac=11×10-11 excess over the value gDirac=2 for the theoretical Dirac point electron suggests for the electron of nature a corresponding excess radius Re-RDirac over the Dirac radius RDirac=0 and a spatial structure. From a plot of measured g and R values for the near-Dirac particles electron, proton, triton, and helium-3, an electron radius Re≈10-20 centimeter is extrapolated. In a speculation, the triton-proton-quark model has been extended to the electron, to a succession of subquarks, and finally to the "cosmon." Rapid decay of a cosmon-anticosmon pair created from the "nothing" state in a spontaneous quantum jump initiated the Big Bang.