I'm wondering why supersymmetry can only be verified in high energy level,can we check supersymmetry in low energy physics?
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3$\begingroup$ not sure why this is getting downvoted, the question should be expanded, but it's a pretty reasonable question $\endgroup$– 4xionCommented Jul 1, 2020 at 0:44
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It can! The question isn't very specific, so I'll only answer broadly. Of course it all depends on what you mean by high and low energies, but many naive supersymmetric models you might write down will affect low-energy physics. If your model predicts that the proton will decay quickly, or that a new particle will be created if you collide two electrons together at 1 GeV, then it's easy to test. But experiments have found that the proton lifetime must be long (greater than $10^{34}$ years), and we know the particles produced by electron scattering at these energies.
The issue is that the Standard Model predicts low-energy physics extremely well. So if the SUSY model modifies low-energy physics in a way we don't observe, then it's wrong.
There are still many experiments not involving particle accelerators which can put bounds on and rule out supersymmetric models, e.g. measurements of the electron electric dipole moment, proton lifetime, dark matter searches, etc.
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$\begingroup$ Thanks for your answer! Just some quick questions: 1. why meausre the electron electric dipole moment can rule out susy models? It seems that the anomolous edm is related to axion, while axion is related to strong cp problem , instead of susy? 2. why measure proton life time? I know that for particle and anti particle , they have the same life time by CPT theorem, however, for particle and its superpartner, I'm not sue if the relationship still holds. $\endgroup$– feng linCommented Jul 1, 2020 at 7:51
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$\begingroup$ 3. you say that experiments have found the lifetime of proton is rather long, I'm wondering how they measure it because it's so long that people cannot observe the decay of the proton(so many years!). $\endgroup$– feng linCommented Jul 1, 2020 at 7:51
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1$\begingroup$ For the first two questions, in a given SUSY model there are new particles that electrons, protons, etc, can interact with or decay into, which can contribute to quantities like the electron EDM. In one of the simplest SUSY models, Georgi-Glashow SU(5), the proton can decay (mediated by a vector boson) and one can estimate the rate at which this happens (the proton lifetime predicted by the SU(5) model was too short and has been ruled out by experiment). $\endgroup$– 4xionCommented Jul 2, 2020 at 4:51
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1$\begingroup$ For 3), you don't need to wait $10^{34}$ years, you can take $10^{34}$ protons (I think this is about the number in Super-Kamiokande), and by not observing anything, you can put statistical bounds on the proton lifetime $\endgroup$– 4xionCommented Jul 2, 2020 at 4:55