MISSING ISOSCALAR MONOPOLE STRENGTH IN NI-58

The giant resonance region in Ni-58 was studied with inelastic scatter ing of 240 MeV alpha particles at small angles including O degrees. It is shown that the total isoscalar monopole strength in the region E(x ) = 12 to 25 MeV is <50% of the EO energy-weighted sum rule, and that the centroid of the EO strength E(GMR) 24.8 MeV in contrast to the E(G MR) approximate to 17 MeV expected from systematics of other nuclei. I f there is similar unobserved EO strength in other nuclei, E(GMR) for those nuclei may be significantly different from those used to extract nuclear matter incompressibility.