Where does one start? In our field, the Standard Model (SM) of particle physics have occupied the place of honour for a great many years due in part to its outstanding success and elegant simplicity. To some of us in the field, the words of Keats, "Truth is beauty, beauty truth" never rang truer. Yet we know that the hour of its demise approaches ever closer. It is after all but an approximation of the truth and will be, with the advent of the Large Hadron Collider (LHC), superseded by another greater theory that will no doubt subsume it and all that went before. This much we have known for some time. As to which theory it will be, that remains to be discovered.

There is certainly no shortage of claimants. Perhaps the mostly widely supported one, where tremendous effort has been expended into its elucidation, is a pretentious sounding pretender named supersymmetry. Relating the interactions of particles in a very specific way, supersymmetry does circumvent some of the limitations of the SM. Traditionally because of the inherent difficulties in obtaining a phenomenologically viable model (in other words, something that looks like our universe), high energy supersymmetry breaking was disfavoured. This is because if we break supersymmetry at high energies, we lose the resolution of the problems one normally in the SM. We end up a theory that is more complicated than the SM but doesn't explain away the problems of the SM.

This is true in a number of cases but it is the exception that is truly interesting. As mentioned earlier, the LHC will be in operation by 2007 and like all hadron colliders, yields a gargantuan number of events, not all of which might be useful. The process of determining whether or not an event is of interest, and ultimately if it is recorded, is often dictated by theoretical considerations. As such there is a very real possibility that we might, as it were, throw the baby out with the bath water. It is therefore incumbent upon us model-builders to consider other realistic possibilities that might well be the UV completion (a fancy way of saying the theory that lies beyond what is currently known) of the SM.

The exception to the conventional picture that I alluded to earlier is the "Supersymmetry without supersymmetry" paradigm. Although supersymmetry is broken at very high energies, additional symmetries and strong dynamics protect the model from the problems that plagued the SM (I might write another short article on the problems of SM in the Layman's Guide one of these days). The end result is a theory that at low energy seems to look like that arising from low-energy supersymmetry but in actuality very different. There are however distinctive phenomenological differences and for more details, you can read hep-th/0309103 and hep-ph/0511301. [Writer's Comments: This paragraph seems to have been rather insubstantial. Several additional concepts need to be introduced before I launch into the specifics of the realization. I'll work on it.]