Neutron Density distributions in $^{204,206,208}$Pb observed via polarized proton elastic scattering at 300MeV

Neutron skin thickness, the difference of root mean square radii of neutron and proton distributions, for $^{208}$Pb provide a key role to discern various effective interactions used in Skyrme Hartree-Fock (SHF) and Relativistic Mean Field (RMF) models. We performed an experiment of elastic scattering of 300MeV polarized protons off $^{204,206,208}$Pb at RCNP and extracted their neutron density distributions in the framework of the relativistic impulse approximation (RIA) with medium modified NN interactions . We will report the results of the neutron skin thicknesses together with the nuclear incompressibility.