A broad resonance has been observed by inelastic scattering of 200 MeV protons from ${}_{}{}^{90}{}_{}{}^{}\mathrm{Zr}$, ${}_{}{}^{92}{}_{}{}^{}\mathrm{Zr}$, ${}_{}{}^{94}{}_{}{}^{}\mathrm{Zr}$, and ${}_{}{}^{96}{}_{}{}^{}\mathrm{Zr}$. This resonance has a sharply forward peaked angular distribution and an excitation energy and strength which strongly suggest that it is the $M1\mathrm{}$ giant resonance. Microscopic distorted wave impulse approximation calculations match the shape of the angular distribution reasonably well. The strength, however, is only about 30% of that predicted.

NUCLEAR REACTIONS ${}_{}{}^{90,92,94,96}{}_{}{}^{}\mathrm{Zr}(p, p^{\prime })$, $E=200\mathrm{}$ MeV, measured $\sigma \left(\theta \right)$, DWBA analysis, enriched targets, deduced levels, resolution 70 keV.

• Received 8 February 1982

DOI:https://doi.org/10.1103/PhysRevC.26.87