The excitation region in ${}^{12}\mathrm{C}$ below $E_x=45\mathrm{}\mathrm{MeV}$ was studied using 240 MeV α-particle scattering. Elastic scattering was measured from ${\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}=3.8\mathrm{}°$ to 49.4° and density dependant folding optical model parameters were obtained. Inelastic scattering to the 4.44 MeV $2^{+},$ 7.65 MeV $0^{+},$ 9.64 MeV $3^{-},$ 10.3 MeV $0^{+},$ and 10.84 MeV $1^{-}$ states was measured and $B\left(\mathrm{EL}\right)\mathrm{}$ values obtained. Inelastic scattering exciting ${}^{12}\mathrm{C}$ to $10\mathrm{MeV}<~E_x<~12.5\mathrm{MeV}$ was measured from $1.4°<~{\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}<~10°$ and to $12.5\mathrm{MeV}<~E_x<~45\mathrm{MeV}$ from $1.4°<~{\theta }_{\mathrm{c}.\mathrm{m}.\mathrm{}}<~16°$ and $E0,$ $E1,$ $E2,$ and $E3\mathrm{}$ strength distributions were obtained. Strength was identified corresponding to 27±5, 78±9, and 51±7% of the isoscalar $E0,$ $E1,$ and $E2\mathrm{}$ energy weighted sum rule (EWSR), respectively, with centroids of 21.9±0.3, 27.5±0.4, and 22.6±0.5 MeV and rms widths of 4.8±0.5, 7.6±0.6, and 6.8±0.6 MeV. Less than 7% of the $E3\mathrm{}$ EWSR strength was identified.

• Received 10 March 2003

DOI:https://doi.org/10.1103/PhysRevC.68.014305