On the neutron charge radius and the new experiments proposed for the precise (n,e)-scattering length measurement

Strict comprehensive treating the generalized Dirak equation for nucleon in external electro-magnetic field argues quite clear that there is no physical reason to bring into consideration so-called “Foldy-term” while obtaining the neutron mean square charge radius < r _n ² >, caused by an electric charge distribution inside a nucleon, from the experimental value of the (ne) — scattering length b _ne , that term being, as a matter of fact, fictitious one. Consequently, the representing of the experimental quantity b _ne as a sum of “Foldy length” b _F and “intrinsic” one b_I, even so splitting the total value of < r _n ² > in “Foldy” and “intrinsic” < r _in ² >, turn out of having no profound physical sense, being rather ambiguous in actual fact. The formal phenomenological relation, originated from the generalized Dirak equation for nucleon, of the quantities b _ne , < r _n ² >, and neutron anomalous magnetic moment μ is inquired. Concise treating < r _n ² > in the frame-work of up-to-date nucleon cloudy bag model (CBM) is presented, no “Foldy term” being emerged, and < r _n ² >, calculated according this approach, provides b _ne -value which is in agreement with experimental result within accuracy of about 10%. On the other hand, the experimental b _ne -value proves to be described phenomenologically through solely the neutron anomalous magnetic moment μ with the same accuracy ～ 10%. Then the necessity of obtaining b _ne -value with more reliable accuracy then in previous experiments becomes obvious, corrections have to be reduced to the level of the precise declared. For these aims, two new proposed experiments have been Monte-Carlo modelled. The first renders the measurement of the energy dependence of an elastic scattering cross-section on ⁸⁶ Kr, having the unique small capture cross-section. The second one is to measure the energy dependence of neutron scattering angle anisotropy for natural Xe.