Elastic vs Inelastic vs isospin violating scattering particle physics models I'm looking for a nice paper that explains the difference between three particle physics models for spin-independent dark matter interaction with nuclei: elastic, inelastic and isospin violating scattering. I've found a nice paper that is giving a nice summation of the current results in direct dark matter searches ( http://arxiv.org/abs/1210.4011 ) and want to read up some more.
Cheers,
Adnan
 A: "Elastic" and "inelastic" mean the same things they do in an introductory mechanics class. In elastic collisions the total mechanical energy is the same after the interaction as before (in a dark matter interaction this means effective the total kinetic energy), while in inelastic interaction that equality can not be counted on. Either some mechanical energy goes into another channel in the final state or some energy that was in another form in the initial state appears in the final state.
Typical possibilities for inelastic interaction would be particle creation, excitation of the struck nucleus, or break up of the target.
"Isospin violating" means that the (approximate) isospin quantum number of the final state is different from that in the initial state. Isospin is the quantum number that distinguishes protons from neutrons (and can be applied to other hadrons as well). A collision that transforms a proton into a neutron without changing the isospin quantum number (if any: it probably doesn't have one) of the dark matter component would be isospin violating (and inelastic because some kinetic energy from the initial state went into raising the mass of the final state).
