Skin values of 208Pb and 48Ca determined from reaction cross sections

Background: The PREX and the CREX group reported skin values,..208 skin (PREX2) = 0.283 +/- 0.071 fm and..48 skin(CREX) = 0.121 +/- 0.026 (exp) +/- 0.024 (model) fm, respectively. Using the Love-Franey (LF)..-matrix folding model with the neutron and proton densities scaled to the neutron radius..208 n (PREX2) and the proton radius of the electron scattering, we found that the reaction cross sections.... reproduce the data for p+ 208Pb scattering at.. lab = 534.1, 549, 806 MeV. Zenihiro et al. deduce neutron radii..48,40 n (exp) from the angular distributions of the cross sections and analyzing powers of proton elastic scattering, whereas we determine matter radius..40 m (exp) = 3.361 +/- 0.075 fm from measured.... for 4He+ 40Ca scattering. Aim: Our first aim is to determine..208 skin from measured.... of p+208Pb scattering at.. lab = 534.1, 549, 806 MeV by using the Love-Franey (LF)..-matrix folding model. Our second aim is to determine..48 skin from the..40 m (exp) and the difference.. =..48 m (exp)-..40 m (exp) that is evaluated from the..48,40 n (exp) and the..48,40 p (exp) calculated with the isotope shift method based on the electron scattering. Method and results: For the first aim, we use the Love-Franey..-matrix model with the densities scaled from the D1S-GHFB+AMP neutron density, where D1S-GHFB+AMP stands for D1S Gogny HFB (GHFB) with the angular momentum projection (AMP). The D1M-GHFB+AMP is also used to estimate a theoretical error. The resulting skin values are..208 skin = 0.324 +/- 0.047 fm for D1S and..208 skin(exp) = 0.333 +/- 0.047 fm for D1M. The difference.. = 0.109 fm and..40 m (exp) = 3.361 +/- 0.075 fm yield..48 m = 3.470 +/- 0.075 fm, leading to..48 skin = 0.144 +/- 0.075 fm. Conclusion: We conclude that..208 skin(exp) = 0.324 +/- (0.047) exp +/- (0.009) th fm for p scattering at.. lab = 534.1, 549, 806 MeV. Our skin value..48 skin = 0.144 +/- 0.083 = 0.061 0.227 fm is consistent with..48 skin (CREX) = 0.071 0.171 fm.

Automated summary

The article discusses the reports on skin values by the PREX and CREX groups, and analyzes the experimental results using the Love-Franey matrix folding model. The study finds that the scattering data can be reproduced within a specific energy range, and provides information about neutron and proton radii.