The excitation function of the 15.11 MeV ($1^{+}$,T=1) state in ${}_{}{}^{12}{}_{}{}^{}\mathrm{C}$ has been measured by using the (π,π’γ) angular correlation technique. By this method, the background can be suppressed substantially. The relative cross section ratio of the 15.11 MeV ($1^{+}$,T=1) and the 12.71 MeV ($1^{+}$,T=0) state as a function of the pion incident energy is found to show a resonancelike behavior in the region of the Δ resonance, in agreement with previous measurements of Morris et al.

• Received 12 November 1987

DOI:https://doi.org/10.1103/PhysRevC.37.2892