Cross sections and analyzing powers for polarized proton elastic scattering from ${}^{58}\mathrm{Ni}$, and ${}^{204,206,208}\mathrm{Pb}$ were measured at intermediate energy $E_p=295$ MeV. An effective relativistic Love-Franey interaction is tuned to reproduce ${}^{58}\mathrm{Ni}$ scattering data within the framework of the relativistic impulse approximation. The neutron densities of the lead isotopes are deduced using model-independent sum-of-Gaussians distributions. Their error envelopes are estimated by a new ${\chi }^2$ criterion including uncertainties associated with the reaction model. The systematic behaviors of extracted error envelopes of the neutron density distributions in ${}^{204,206,208}\mathrm{Pb}$ are presented. The extracted neutron and proton density distribution of ${}^{208}\mathrm{Pb}$ gives a neutron skin thickness of $\Delta r_{\mathit{np}}={0.211}_{-0.063}^{+0.054}$ fm.

• Received 12 September 2010

DOI:https://doi.org/10.1103/PhysRevC.82.044611