Nuclear charge form factors of helium isotopes with configuration mixing
Nuclear charge form factors of 3He and 4He have been calculated with configuration mixing up to 3hw in the first-order perturbation theory. It is observed that only (2s) excitation contributes to the nuclear form factor, all other states contributions vanish. We have shown that the mixing configuration in 3He and 4He which is due to residual two-body interaction is important. The residual interaction being used is Reid Soft Core type which gives correct excitation energy of 4He of the first excited state. The admixture coefficients of the order of 8% for 3He and 12% for 4He nuclide are obtained. The configuration mixing improves the form factor substantially over the one without any configuration mixing for both 3He and 4He nuclide for low momentum transfer. Short-Range-Correlation (SRC) of Jastrow type when invoked improves the agreement of calculations with the experimental data to some larger momentum transfer but does not reproduce the second minimum. At large momentum transfer the electron scattering from these light nuclide is able to give finer details of the interior features of the nucleons within the nucleus, where quark degrees of freedom seem to be important. D-state with SRC has shown second minimum and third maximum, though much smaller.