Measurements of angular correlations between two photoelectrons in the1P0symmetry

Double photoionization experiments on Xe (. . .5p 6 ) using a helium discharge lamp have been performed in a plane perpendicular to the unpolarized photon beam. Of special concern is the case where the Xe 2+ ion is left in its excited (. . .5p 4 1 S e ) state. Angular measurements performed with equal energies of the two electrons clearly show that the cross section is nearly zero when they are emitted in opposite directions. This is consistent with the properties of two electrons of 1 P 0 symmetry. These measurements give direct information on the correlation which originates in the three-body interaction between the ion and the two electrons.