Speaker
Description
The charge density distributions of nuclei are best determined by elastic electron scattering, and the stable nuclei that have been studied so far have played an essential role in revealing their internal structure.
Recently it was pointed out theoretically that the 4th moment of the charge density distribution, <r_c^4>, contains the information of neutron-distribution radius^([1]).
Experimental determination of <r_c^4> can be two methods;
1) the form factor F(q) (where q is the momentum transfer) is measured from elastic electron scattering cross section and calculated using the charge density distribution ρ(r) obtained as its Fourier transform, and 2) obtained without ρ(r) via Taylor expansion of F(q) at low q region.
The neutron radius of ²⁰⁸Pb, whose charge density is the most precisely known, has been extracted from <r_c^4> following the method 1), and has been found to be consistent with the parity-violating electron scattering results performed out at JLab.
We are currently conducting the method 2) to extract <r_c^4> from the elastic cross section of ²⁰⁸Pb to be measured with ULQ2 facility. The required precision for the cross section is the order of 10⁻³ to determine the neutron-distribution radius accurately.
I will discuss the current status and perspectives of this project.
