is super symmetry real or has been predicted by string theory?
- There is no experimental evidence for supersymmetry, yet. A lot of people set hope into the Large Hadron Collider at CERN (european center for nuclear and particle physics) to find superpartners of known particles and hence (more or less) prove susy to exist.
- It's not a prediction by string theory but a necessary component of some string models (hence the name superstrings)*. It's not something unique to string theory, though. You can apply supersymmetry more or less directly to the SM which in the minimal version of a realistic model leads to the minimal supersymmetric standard model (MSSM), which might well be the most-examined model for physics beyond the standard model.
*: I'm not a stringer. It might be that it's a fundamental building block for all string models as some SUSY guy told me. However, since some stringer told us in a talk that there's string models with susy and string models without, I'm more inclined to believe that version, even though that information is a bit older.
All true, but it is still worth saying that it is really only in string theory that supersymmetry arises naturally.
Taking the maximum extension of spacetime symmetries already appears relatively natural () to me. How does it "arise naturally" in string theory (also in the sense of "what does that mean?") and what does that mean about string models without susy? If susy automatically arises from a string approach, then it seems that non-susy string models shouldn't be possible.
Yes, I would be glad to know how does susy appear in string theory ? Is it a consequence of strings or extra-dimensions (which can be wo strings) or both or something else ?
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