Using a disk or hoop to measure the width of a string?
Particle Radius, R = kq^2/E
Electron energy E = mc^2 = 8.19E-14 Joule
R = 3.72E-15 meters or Fermi
Disk or Hoop (string circles ?)
Proton energy E = mc^2 = 1.49E-10 Joule
R = 2.0E-18 meters
Or with 3 stacked "quark circles" making a proton
E = 1.49E-19/3 Joule
E = 4.98E-11 Joule
Stack Radius R = 6.0E-18 meters
"The scattering of electrons from nuclei has given us the most precise information about nuclear size and charge distribution. The electron is a better nuclear probe than the alpha particles of Rutherford scattering because it is a point particle and can penetrate the nucleus.
For low energies and under conditions where the electron does not penetrate the nucleus, the electron scattering can be described by the Rutherford formula."
"As the energy of the electrons is raised enough to make them an effective nuclear probe, a number of other effects become significant, and the scattering behavior diverges from the Rutherford formula. The probing electrons are relativistic, they produce significant nuclear recoil, and they interact via their magnetic moment as well as by their charge."
