Are there scalar partners for the Z and W particles in massive SUSY multiplets?

  • Thread starter arivero
  • Start date
  • Tags
    Scalar
In summary: Dirac particle.This is all very confusing, and I'm not sure if you are asking about the Dirac particle or the Dirac Gaugino. In summary, the MSSM should predict the existence of scalar partners for the Z and W, as well as new chiral fermion for each. The Dirac Gaugino is a particle made of two Weyl spinors that have opposite charges.
  • #1
arivero
Gold Member
3,429
140
Does anybody remember some reference to models where the Z and W particles are in massive susy multiplets of vector type?

Such models should predict, besides the zino and wino, scalar partners for the Z and W, as well as new chiral fermion for each (probably the later should be able to combine with the wino and zino).

And, does the MSSM predict such content too? Or is it different because susy breaks before than electroweak?
 
Physics news on Phys.org
  • #2
arivero said:
Does anybody remember some reference to models where the Z and W particles are in massive susy multiplets of vector type?

Such models should predict, besides the zino and wino, scalar partners for the Z and W, as well as new chiral fermion for each (probably the later should be able to combine with the wino and zino).

And, does the MSSM predict such content too? Or is it different because susy breaks before than electroweak?

so you want to embed the gauge sector into an N=2 susy theory? There are plenty of suggestions to do this (including a few published by yours truly! :wink: just look for references to "Dirac Gauginos"). MSSM has a purely N=1 content, so the vector bosons are part of a massless vector multiplet (Majorana gauginos), and they get mass from the N=1 Higgs multiplet, just like the usual SM.
 
  • #3
blechman said:
MSSM has a purely N=1 content, so the vector bosons are part of a massless vector multiplet (Majorana gauginos), and they get mass from the N=1 Higgs multiplet, just like the usual SM.

It seems that people is biased because normally you first break supersymmetry and then later you break electroweak symmetry. But you can first break electroweak symmetry and still kept supersymmetry, leaving for a next step its breaking.

And then, independently of the mechanism of electroweak symmetry breaking, the pure N=1 massive vector multiplet contains a massive vector, four fermionic components, and one scalar. Is the only way you can build a massive multiplet in N=1. In fact it is in the first pages of the textbooks I am reading now (Terning's).

Of course, when the mechanism of electroweak symmetry breaking is the higgs, the scalars are higgses (just as the zero helicity state is also a higgs eaten by the vector). But I am interested in the agnostic case and how far can one go with it.

Hmm are you telling me that the N=1 massive case is equal to the N=2 massless?
 
Last edited:
  • #4
In any case, the first question that is perturbing me now is, has this Dirac Gaugino all their four components with the same electric charge?
 
  • #5
I am confused by your accusation of "bias" (although I see you rewrote the statement...). I am only defining the "MSSM" (emphasis on the first M = MINIMAL).

So the first criticism to your suggestion is that if SUSY is broken at a scale below the weak scale, then we should see SUSY particles with masses below the W/Z mass, which we don't.

Furthermore, if SUSY is supposed to solve the "gauge hierarchy problem" it would seem very strange to demand EWSB happens at a HIGHER scale than SUSY breaking. Part of the beauty of the MSSM is that EWSB occurs for free!

As to your statement about N=1 vs N=2: the massive N=1 multiplet is the same as the massless N=2 multiplet. Keep reading Terning.

Finally about the Dirac gaugino: I'm confused what you are asking. You want there to be two (Weyl) fermions to make a massive gaugino. These are like the electron and positron that make the Dirac Electron. There is no problem with charges - one of the Weyl spinors makes a particle and the other makes the antiparticle, as CPT requires. nrqed and I had a running thread on this a while back.
 
  • #6
But if the two Weyl spinors are in the same supermultiplet, is it possible to put them in the same Dirac particle? I guess not.

I suposse that the scheme in the SMM is that the two spinors in the W+ supermultiplet build two dirac spinors joining with the two spinors in the W- supermultiplet. On other hand, the two spinors in the Z0 supermultiplet should combine between themselves, and I am a bit puzzled about it.
 
  • #7
Why is it a problem that particles of equal and opposite charges are in the same multiplet? The electron and the positron are in the same Lorentz multiplet (the Dirac spinor) that that doesn't seem to be a problem! As SUSY is a spacetime symmetry, the analogy is more or less exact. It's not a problem.

A massive vector multiplet can be thought of as a massless vector + chiral multiplet. One spinor is the spinor in the vector multiplet, and the other is the spinor in the chiral multiplet. Then these two spinors have opposite charges, as they must have to avoid anomalies.

Ws and Zs are a little more complicated because there is the added complication of electroweak symmetry breaking. This is why we never talk about "zinos" and "photinos". Rather, you should say that the neutral wino and the "bino" (weak hypercharge gaugino) have partners.

In this (weak isospin) basis, we also do not talk about W+ or W-, but W1 and W2. It is THESE gauginos that get doubled, and then various combinations of them become charged after electroweak symmetry is broken to electromagnetism.
 
  • #8
blechman said:
In this (weak isospin) basis, we also do not talk about W+ or W-, but W1 and W2. It is THESE gauginos that get doubled, and then various combinations of them become charged after electroweak symmetry is broken to electromagnetism.

OK, I was not putting attention to this point. It is very important to me to understand all this mixing of charges.

Particularly, what I am guessing is that if a fermion is not Dirac, it can not see the electric charge. And, that still it should see the chiral interactions.
 
Last edited:

What are the scalar () partners of W,Z?

The scalar partners of W and Z are known as the W' and Z' particles, respectively. They are hypothetical particles predicted by some extensions of the Standard Model of particle physics.

Why are the scalar () partners of W,Z important?

The existence of scalar partners of W and Z could provide a better understanding of the fundamental forces of nature and help explain phenomena such as dark matter and the hierarchy problem. They could also play a role in the unification of the electromagnetic and weak forces.

How are the scalar () partners of W,Z different from the W,Z bosons?

The W and Z bosons are known to have spin 1, while their scalar partners are predicted to have spin 0. This means that they have different properties and interactions with other particles.

What evidence do we have for the existence of the scalar () partners of W,Z?

Currently, there is no direct experimental evidence for the existence of the scalar partners of W and Z. However, some theories, such as supersymmetry, predict their existence and are actively being tested at high-energy particle colliders.

Could the scalar () partners of W,Z be discovered in the future?

Yes, with ongoing advancements in technology and the continuing exploration of particle physics, it is possible that the scalar partners of W and Z could be discovered in the future. Their discovery would provide important insights into the fundamental nature of the universe.

Similar threads

Replies
4
Views
2K
  • High Energy, Nuclear, Particle Physics
Replies
7
Views
2K
  • Beyond the Standard Models
Replies
5
Views
2K
  • Beyond the Standard Models
Replies
2
Views
2K
  • Beyond the Standard Models
3
Replies
74
Views
9K
  • Beyond the Standard Models
Replies
2
Views
2K
Replies
4
Views
1K
  • Beyond the Standard Models
Replies
1
Views
2K
  • Beyond the Standard Models
Replies
1
Views
3K
Replies
1
Views
2K
Back
Top