The Giant Monopole Resonance in the $^{112-124}$Sn Isotopes and the Symmetry Energy Term in Nuclear Incompressibility

We have investigated the isoscalar giant monopole resonance (GMR) in the Sn isotopes, using inelastic scattering of 400-MeV $alpha$-particles at extremely forward angles, including 0 deg. A value of -550 pm 100 MeV has been obtained for the asymmetry term, $K_tau$, in the nuclear incompressibility.