Neutron skin thickness of 116,118,120,122,124Sn determined from reaction cross sections of proton scattering

The cross sections of the isovector spin-dipole resonances (SDR) in Sb isotopes have been measured. Within model used, neutron-skin thicknesses rskin(exp) deduced 0.12±0.06 fm for 116Sn, 0.13±0.06 118Sn, 0.18±0.07 120Sn, 0.22±0.07 122Sn, 0.19±0.07 124Sn. We tested chiral (Kyushu) g-matrix folding 12C+12C scattering, and found that Kyushu is reliable reaction σR 30˜<Ein˜<100MeV 250˜<Ein˜<400MeV. determine neutron skin thickness rskin(exp), using measured 4He+116,120,224Sn scattering. results are rskin(exp)=0.242±0.140 rskin(exp)=0.377±0.140 rskin(exp)=0.180±0.142 available proton scattering on 116,118,120,122,124Sn with high accuracy 2∼3% as a function incident energy Ein. Our aim to small errors by model. densities scaled from D1S-GHFB+AMP density, where stands Gogny-D1S HFB (D1S-GHFB) angular momentum projection (AMP). radii agree those calculated isotope shift method based electron then scale so reproduce σR(exp). In 30˜<Ein˜<65MeV, we σR. values rskin(exp)=0.118±0.021 0.112±0.021 0.124±0.021 0.156±0.022 As value 30˜<Ein˜<50MeV 0.122±0.024 fm. consistent previous values.