TY - JOUR AU - PRYCE, M. H. L. AU - WARD, J. C. PY - 1947 DA - 1947/09/01 TI - Angular Correlation Effects with Annihilation Radiation JO - Nature SP - 435 EP - 435 VL - 160 IS - 4065 AB - If the two gamma-quanta emitted on the annihilation of a slowly moving positron-electron pair both undergo a Compton scattering, in view of the fact that they are polarized in perpendicular directions, it is reasonable to expect that the scatter distributions will be correlated in azimuthal angle. Fig. 1 shows the expected state of affairs. It has recently been proposed by R. C. Hanna to detect this effect, using counters to observe coincidences of the scattered quanta. With the view of assisting the design of the experiment, we have calculated the magnitude of the effect to be expected. We find that the differential double cross-section is given by SN - 1476-4687 UR - https://doi.org/10.1038/160435a0 DO - 10.1038/160435a0 ID - PRYCE1947 ER -