Neutron skins of ${}^{208}$Pb and ${}^{48}$Ca from pionic probes

Abstract

The neutron skin of ${}^{208}$Pb has received considerable attention in recent years. A variety of strongly-interacting probes depict a rather consistent picture but pionic probes have not been referred to in this context. We present here neutron-skin values from pionic atoms and from total reaction cross sections of ${\pi }^{+}$ between 0.7 and 2 GeV/c which fit well into the picture. In addition we show that a neutron skin for ${}^{48}$Ca can be obtained from existing data on pionic atoms and the result agrees with pion scattering experiments and with the scattering of $\alpha$ particles.

Comments: 9 pages, 3 figures, to be published in Nuclear Physics A