Let's say I have one particle disintegrating, into 3 product , like b---> s + (l+) + (l-) where b is the b quark, s is the s quark and and i have a letpon and anti-lepton. I have calculated for example for a certain penguin diagram, the Wilson coefficients and the operators, or in simple words i have the effective Hamiltonian, how can i proceed from here, knowing the Eff H, to determine what kind of angular distribution the leptons are in? I know this probably basic stuff but for some reason i can't find any reference for this, either i'm doing something wrong, or ???