# Parametrisation of general MSSM/SUSY based on collider experiment observables

The full MSSM contains 120 parameters. In SUSY searches, one usually picks a model like MSUGRA which makes a few assumptions and only has 5 free parameters like $m_0$, $m_{1/2}$, ....

Now, I'm wondering if there is a way to look at supersymmetry in a more phenomenological way, and parametrize it by (low-energy) coupling constants or branching ratios, cross sections of particles, etc.

The way it's done now is that you, for example, make a couple of assumptions at the GUT scale and then work your way down using the renormalization group equations. Also you make specific assumptions about the breaking mechanism.

What I'd like to do is to say: Give me a model / a subset of parameter space where we have light chargino like particles decaying such and such. Or where those particles have couplings in such and such region. Or where the lightest squark like particle is heavier than X GeV. One would probably have to speak of a "lightest strongly interacting superpartner" etc. since the parametrisation would not be sufficent to determine the model completely. As an experimentalist, I could live with it - it would even be interesting - if the theory (after implementation in a MC generator) would give me several different sets of MC for a given query, say one with a lowest cross section bound, one with the highest cross section, etc.

The reason for this is to simply assess what kinds of SUSY are findable by our accelerators, and also to have a parametrisation that gives certain experimentally similar final states similar model parameters.

Is someone working on this, or is it a pipe dream?

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