Transverse Isotropy in Identical Particle Scattering
  It is pointed out that the cross section for the scattering of identical charged bosons is isotropic over a broad angular range around 90 degrees when the Sommerfeld parameter has a critical value, which depends exclusively on the spin of the particle. A discussion of systems where this phenomenon can be observed is presented. 
L.F. Canto, R. Donangelo and M.S. Hussein