4 ms·
What would the 5th dimension be?
by 3rd3 12y ago
What would the 5th dimension be?
- danbruc 12y agoI am not a physicist, therefore this may be complete nonsense. Anyway, as far as I understand it, supersymmetry (all models or only some, I have no idea) adds a new dimension (with non-commutative coordinates?) and when a particle moves along this dimension it turns from a fermion into a boson or vice versa. You take a electron and move it a bit along this dimension and it turns into a photon, you move it back and it becomes an electron again. (Electron and photon are not superpartners, the electron would actually become a selectron, the photon a photino with the photino being one of the candidates for dark matter.)
- orbifold 12y agoI've taken courses on supersymmetry and string theory and this is mostly incorrect. The details are fairly complicated, but the general idea is that there are a few essentially unique supersymmetric theories in 10 dimensions that can be "compactified" to a vast variety of effective theories in four dimensions. From a purely phenomenological point of view that can be ignored however and people have come up with various supersymmetric extensions of the standard model of particle physics in four dimensions going by names like MSSM (minimal supersymmetric standard model), basically introducing aditional superpartners of known particles by hand (like the selectron and photino you mentioned) and "completing" the model by computing the deficit for it to be supersymmetric. Those completions are not unique and can be distinguished by the energy scales they introduce new particles at. One major motivation is to constrain the running of the Higgs mass, which sets a natural upper bound for the expected masses of supersymmetric particles to be found. Those bounds have already almost been excluded by the current data, which is scary or exiting depending on who you ask.