I wrote: It seems like the cross section would drop off with the square of the > distance from the spectator nucleus. Perhaps something like this: > > σ(r) = 1/(1 + A*r^2), > > where A is a constant that is empirically determined; e.g., > > http://i.imgur.com/eWu4K1i.jpg >
Another important parameter would be the energy. Perhaps if you multiplied the normal d+d cross sections by the curve above you would get a suitable function for σ(E,r). Also, I seem to be treating σ as a 0-1 number probability, but I don't think that's how it generally is treated. Eric
