Proton-Proton Scattering Near the Interference Minimum

The differential proton-proton scattering cross section at 45° in the laboratory system has been measured in the energy region 350-420 kev. The interference minimum occurs at 383.9±1.5 kev. The minimum in the ratio to the Mott cross section thus occurs at 382.8±1.5 kev, and at the latter energy the $S$-wave phase shift is ${\delta }_0=0.2527\mathrm{}\pm 0.0011$ radians, in good agreement with the most recent data in this energy region. The combination of our point with the Wisconsin data alone agrees with the previous analysis of data from a wide range of energies.