What is the dependence between multiple scattering (Moliére formula) and the mass of incident particles? I'm reading on my book: "the effect of multiple scattering is generally small for heavy charged particles" but I really can't find a correlation with mass in the Molière formula, while the Rutherford cross section for single scattering seems to INCREASE with mass, for particles with same momentum: so it's proportional to (m/p2)2. I haven't found neather a plot of Moliére probability distribution for different particles. Can you explain me why the text says so? In formulae and/or by logic. Thank you. EDIT: (m/p2)2 instead of (m/p)2.