  We show in the Skyrme-Hartree-Fock approach that unambiguous correlations
exist between observables of finite nuclei and nuclear matter properties. Using
this correlation analysis to existing data on the neutron skin thickness of Sn
isotopes, we find important constraints on the value E_{sym}(rho_0) and density
slope L of the nuclear symmetry energy at saturation density. Combining these
constraints with those from recent analyses of isospin diffusion and double
neutron/proton ratio in heavy ion collisions leads to a value of L=58\pm 18 MeV
approximately independent of E_{sym}(\rho_0).

Nuclear Theory;Solar and Stellar Astrophysics;Nuclear Experiment