Are Force carriers real or not

[ftr]

from QFT wiki
" In QED, the electromagnetic force between two electrons is caused by an exchange of photons. Similarly, intermediate vector bosons mediate the weak force and gluons mediate the strong force in QCD. The notion of a force-mediating particle comes from perturbation theory, and does not make sense in the context of non-perturbative approaches to QFT, such as with bound states."

Then how is it that experiments detect W,Z,PI ...

 

[Demystifier]

Experiments detect W, Z, photons etc. as final scattering states, not as intermediate force carriers.

 

[ftr]

Experiments detect W, Z, photons etc. as final scattering states, not as intermediate force carriers.

So modern physics particles play hide and seek. Just like the higgs particle, its field cannot be detected and the particle itself does not exist naturally but we can recreate them in experiments, i.e. give their vacuum enough energy by exciting the constituent fields of the proton with a lot of energy to overspill to the higgs field. Something similar with W, Z in actual nature they don't exist their "virtual" exist hence their fields must be their and we must pump energy into their fields to find them by our lucky star process that converts them to gama rays for us to detect. Say, not even Morgan Freeman can make it so melodramatic.

Seriusly, is my description approximately correct, if not why not. Thanks

 

[PeterDonis]

how is it that experiments detect W,Z,PI

Because they're not measuring them indirectly by measuring the effects of the interactions they mediate on other particles. They are measuring them directly by pumping enough energy into the system to make W, Z, etc. particles without them mediating any interactions.

Just like the higgs particle, its field cannot be detected

Sure it can. Just not directly. But it has plenty of indirect effects, such as the masses of the W and Z bosons. That's how physicists knew roughly what kind of device they would need to build to make Higgs particles directly.

he particle itself does not exist naturally but we can recreate them in experiments

Sure. What's wrong with that? We did the same thing with all of the chemical elements beyond uranium (plus technetium and prometheum, both of which are lighter than uranium). They don't occur naturally, but we can make them in experiments. Does that mean they are playing "hide and seek"?

 

[ftr]

Thank you PeterDonis. Can you make a comment regarding the red text in the OP.

 

[PeterDonis]

Can you make a comment regarding the red text in the OP.

What about it? The statement is perfectly true, and doesn't mean what you apparently think it means. Is that what you wanted to know?

 

[ftr]

doesn't mean what you apparently think it means.

What do you think it means?

 

[PeterDonis]

What do you think it means?

Just what it says: the notion of "force carrier particles" does not make sense outside of perturbation theory. Which has nothing to do with how experiments detect W, Z, etc., because, as @Demystifier and I have explained, experiments don't detect "force carrier particles", they detect particles that aren't mediating any interactions.

 

[ftr]

Just what it says: the notion of "force carrier particles" does not make sense outside of perturbation theory. Which has nothing to do with how experiments detect W, Z, etc., because, as @Demystifier and I have explained, experiments don't detect "force carrier particles", they detect particles that aren't mediating any interactions.

To me I interpret the wiki as saying there may not be a mediating particle as such, so why do we insist that we can detect them even though they are artifacts of the method.

 

[mfb]

To me I interpret the wiki as saying there may not be a mediating particle as such, so why do we insist that we can detect them even though they are artifacts of the method.

The direct detection of W,Z and Higgs has nothing to do with perturbation theory. It is a completely different method. What you quoted is irrelevant for it.

 

[ftr]

The direct detection of W,Z and Higgs has nothing to do with perturbation theory. It is a completely different method. What you quoted is irrelevant for it.

That is not what I said.

 

[protonsarecool]

W, Z etc. are not "mediating" particles per se. They are just real particles, corresponding to fields which show up in the standard model lagrangian. As such, they are still there in non-perturbative QFT. In perturbation theory, they can show up as "external legs" in Feynman diagrams, ie. as actual particles coming in or out of scattering processes, OR they can show up as internal lines, or "virtual particles". Now, you can (and should) say that virtual particles don't really "exist" in any meaningful way, since they are just the product of a perturbative expansion and don't show up in non-perturbative methods. But they still have "real" counterparts, which do exist outside of perturbation theory (and which we can actually measure)!

 

[mfb]

That is not what I said.

That is exactly the problem.

 

[ftr]

they are still there in non-perturbative QFT

Ok thanks. Can you give reference please.

 

[protonsarecool]

Just observe that they are part of the standard model lagrangian http://www.fe.infn.it/~bettoni/particelle/Strong/SMLagrangian.pdf , which defines the standard model QFT. This is completely independent from which mathematical method you choose to use for further study (like perturbation theory, lattice models, "exact" methods like functional RG,...). As for the observation part: https://arxiv.org/pdf/hep-ex/0702027.pdf First hit on arxiv (among 1000s of others).

 

[PeterDonis]

I interpret the wiki as saying there may not be a mediating particle as such, so why do we insist that we can detect them even though they are artifacts of the method.

Your interpretation is wrong. Saying that the concept of "force carrier particle" does not make sense outside of perturbation theory is not the same as saying that W, Z, etc. are "artifacts of the method". They're not. They are real quantum fields, which under appropriate conditions take on states that can be detected as real particles by our detectors. The only "artifact of the method" is viewing terms in a mathematical perturbation expansion as "force carrier particles"; but these "particles" are not the same as the particles detected by our detectors. They are different states of the quantum fields; the fact that the word "particle" happens to appear in the ordinary language description of both is irrelevant to the actual physics.

Can you give reference please.

No, you need to give a reference--a textbook or peer-reviewed paper, not a Wiki article--that supports your claims if you want to continue making them despite the corrections you have already received. And at this point you will need to do so by PM to me, since I am closing this thread because the question you asked has already been answered, repeatedly.