  The Relativistic Mean Field (RMF) theory is applied to the analysis of
ground-state properties of Ne, Na, Cl and Ar isotopes. In particular, we study
the recently established proton skin in Ar isotopes and neutron skin in Na
isotopes as a function of the difference between the proton and the neutron
separation energy. We use the TMA effective interaction in the RMF Lagrangian,
and describe pairing correlation by the density-independent delta-function
interaction. We calculate single neutron and proton separation energies,
quadrupole deformations, nuclear matter radii and differences between proton
radii and neutron radii, and compare these results with the recent experimental
data.
