Moments of the Charge Distribution Observed through Electron Scattering in 3H and 3He

Abstract The moments of the charge distributions obtained by the sum-of-Gaussians (SOG) analysis of electron-scattering data are examined in $^3$H and $^3$He, together with those obtained by the Fourier–Bessel (FB) analysis. The SOG and FB methods reproduce well the experimental form factors available at present, but provide different charge distributions from each other. As a result, they do not yield the same values of the moments of the charge distribution, although their analyses are called “model-independent.” The moments are sensitive to the tail of the charge distribution. The present experimental data are not enough for SOG and FB analyses to determine with reasonable accuracy the shape of the tails, in a quantum mechanical point of view. New, accurate experimental data at small momentum transfer squared less than 0.1 fm$^{-2}$ are desired.