Attempt to determine the shape of the region from which cumulative protons are emitted

The shape of the region of production of cumulative particles has been studied by analysis of the distributions of pairs of cumulative protons emitted from Pb nuclei in the longitudinal and transverse components of the difference of their momenta. Indications are obtained that this region is nonspherical: The dimension which is longitudinal with respect to the direction of the incident particle is greater than the transverse dimension.