New 1.029-GeV $p$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ data and new 1.05-GeV data are in excellent agreement with multiple-diffraction-theory predictions. The theoretical calculations include spin and isospin dependence of the $\Delta$-intermediate-state process and show that it fills the first diffraction minimum. The recently normalized data from Centre d'Etudes Nucléaires de Saclay and the older data from Brookhaven National Laboratory disagree with our calculations and the new data.

• Received 22 February 1977

DOI:https://doi.org/10.1103/PhysRevLett.38.1269