We have measured the first complete angular correlations of α-particle emission from the ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ isoscalar giant quadrupole resonance (${\mathrm{GQ}}_0$R) following excitation by inelastic electron scattering, for momentum transfers from 0.24 to 0.61 ${\mathrm{fm}}^{\mathrm{-}1}$. Analysis of these uniquely determines the ${\mathrm{GQ}}_0$R strength distribution for the ${\mathrm{\alpha }}_0$ channel and sets limits on that for ${\mathrm{\alpha }}_1$.

• Received 8 February 1993

DOI:https://doi.org/10.1103/PhysRevLett.70.2872