IsoscalarE0,E1,andE2strength in40Ca

Abstract

The giant resonance region from $10<{E}_{x}<55\mathrm{MeV}$ in ${}^{40}\mathrm{Ca}$ has been studied with inelastic scattering of 240-MeV \ensuremath{\alpha} particles at small angles including 0\ifmmode^\circ\else\textdegree\fi{}. Strength corresponding to $97\ifmmode\pm\else\textpm\fi{}11%,$ $108\ifmmode\pm\else\textpm\fi{}12%,$ and $62+10--20%$ of the isoscalar $E0,$ $E2,$ and $E1$ sum rules, respectively, was identified with centroids of $19.18\ifmmode\pm\else\textpm\fi{}0.37\mathrm{MeV},$ $17.84\ifmmode\pm\else\textpm\fi{}0.43\mathrm{MeV},$ $23.36\ifmmode\pm\else\textpm\fi{}0.70\mathrm{MeV},$ and rms widths of $4.88\ifmmode\pm\else\textpm\fi{}0.57\mathrm{MeV},$ $2.89\ifmmode\pm\else\textpm\fi{}0.60\mathrm{MeV},$ and $5.34\ifmmode\pm\else\textpm\fi{}0.90\mathrm{MeV}.$