It may therefore seem that DSR theories are ”empty”, in the sense that the new definitions of E and p are merely mathematical manipulations without any physical meaning, i.e. e and p represent the true energy and momentum that one would measure. For a discussion of this point see [203, 186Jump To The Next Citation Point]. Since this is not a theoretical paper, we simply make the DSR assumption that E and p are the measurable energy and momentum (or more specifically for analysis of particle interactions, the energy and momentum that are assigned to in and out states in a scattering problem).