Compression-mode resonances in the calcium isotopes and implications for the asymmetry term in nuclear incompressibility

Abstract Recent data on isoscalar giant monopole resonance (ISGMR) in the calcium isotopes 40,44,48Ca have suggested that K τ , the asymmetry term in the nuclear incompressibility, has a positive value. A value of K τ > 0 is entirely incompatible with present theoretical frameworks and, if correct, would have far-reaching implications on our understanding of myriad nuclear and astrophysical phenomena. This paper presents results of an independent ISGMR measurement with the 40,42,44,48Ca( α , α ′ ) reaction at E α = 386 MeV. These results conclusively discount the possibility of a positive value for K τ , and are consistent with the previously-obtained values for this quantity.