- #1
orricl
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If susy really exist in nature, why does it not exist between leptons or quarks and gauge bosons such as photons, weak currents or gluons in the standard model?
Why Don't SUSY Leptons and Quarks Exist Alongside Standard Model Bosons?
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Discussion Overview
The discussion revolves around the existence of supersymmetry (SUSY) and its implications for the relationship between leptons, quarks, and gauge bosons in the Standard Model. Participants explore theoretical aspects of SUSY, including the nature of particle partners and the concept of R-parity, while addressing the original poster's question regarding the absence of SUSY partners alongside known particles.
Discussion Character
- Exploratory
- Technical explanation
- Debate/contested
Main Points Raised
- Some participants question the interpretation of the original poster's (OP) question regarding the relationship between leptons, quarks, and gauge bosons in the context of SUSY.
- Others clarify that supersymmetry, if it exists, posits that every particle has a corresponding partner, but this does not imply a direct relationship between known particles and their SUSY counterparts.
- A participant notes that the supersymmetry framework requires consideration of multiplets with particles differing by half-integer spin.
- There is a discussion about the role of R-parity in SUSY and its implications for particle interactions and symmetries.
- One participant suggests that the OP's question might be interpreted as asking why the fundamental bosons of the Standard Model cannot be superpartners of the fundamental fermions, highlighting the complexity of balancing these relationships within the framework of SUSY.
- Another participant expresses skepticism about the OP's continued interest in the discussion, given the lack of clarification from the OP.
Areas of Agreement / Disagreement
Participants express differing interpretations of the OP's question and the implications of SUSY. There is no consensus on the meaning of the OP's inquiry or the nature of the relationship between particles in the context of SUSY.
Contextual Notes
Some discussions hinge on the interpretation of terms and concepts related to SUSY, such as R-parity and the representation of particles within gauge groups. There are unresolved assumptions regarding the OP's intent and the implications of SUSY on particle physics.
- #2
mfb
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What do you mean with "between leptons or quarks and gauge bosons"? That does not make sense.
Supersymmetry (if it exists) gives every particle a corresponding partner (a bit more in the Higgs sector). We know that all known particles are not supersymmetric partners of other known particles.
Supersymmetry (if it exists) gives every particle a corresponding partner (a bit more in the Higgs sector). We know that all known particles are not supersymmetric partners of other known particles.
- #3
arivero
Gold Member
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mfb said:
This is a twist of the English language I am never sure of: Does "a particle" mean "one particle", or "at least one"? Because of each Weyl fermion we get two scalars.
- #4
mfb
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I don't want to go into details how to count particles, as I don't think it helps here.
- #5
haushofer
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Because the supersymmetry forces you to consider multiplets with particles which differ by (steps of) spin 1/2.
- #6
arivero
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Reading again the OP question, I think it asks for R-parity.
- #7
haushofer
Science Advisor
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Ah, ok. I would say that these fermionic superpartners of the gauge bosons must sit in the same rep. of the gauge group, namely the adjoint. This is because gauge transfo's commute with susy. But quarks and leptons sit in the fundamental rep.
- #8
ChrisVer
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arivero said:
You have a good sense of imagination if you interpreted that question as a question on "R-parity"
...I think you can show that the susy algebra allows for an extension of U(1)-symmetry , whose generators follow certain algebra relations.
Also if I recall well, this extra symmetry can send some parameters in the Lagrangian to be very small to avoid e.g. proton decay with unreasonable lifetime...
Last edited:
- #9
Vanadium 50
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We've got 7 messages guessing what the OP meant. He's been back several times since he posted his question. Since he hasn't clarified it, I'd guess he no longer is interested in it, so all this arguing about what he means is probably futile.
- #10
ohwilleke
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Just for fun, I'll provide my reading of the OP:
I think the OP is asking, "why can't the Standard Model fundamental bosons be the superpartners of the Standard Model fundamental fermions?" The notion is that is supersymmetry is a symmetry between fundamental bosons and fundamental fermions. So, why don't the ones we have balance out without the need to hypothesize new sparticles to do the balancing.
The answer to that question is, that in SUSY the balancing is tautologically obvious which makes a variety of mathematical questions of broader concern in quantum physics much simpler. Any balancing between fermions and bosons in the Standard Model has cryptic origins that are not part of the Standard Model itself and are not understood at this time.
I think the OP is asking, "why can't the Standard Model fundamental bosons be the superpartners of the Standard Model fundamental fermions?" The notion is that is supersymmetry is a symmetry between fundamental bosons and fundamental fermions. So, why don't the ones we have balance out without the need to hypothesize new sparticles to do the balancing.
The answer to that question is, that in SUSY the balancing is tautologically obvious which makes a variety of mathematical questions of broader concern in quantum physics much simpler. Any balancing between fermions and bosons in the Standard Model has cryptic origins that are not part of the Standard Model itself and are not understood at this time.
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