Breaking news from...WIKIPEDIA???

[questionposter]

I thought gluons were only theory, but are gluons actually real observable particles that I can observe with a particle collider I build myself? Do I actually have to start worrying about those stupid extra dimentions of folding?

 

Wikipedia says they were proven to exist some time ago, but I even talked to real physicists since that time and they only talked about them in the context of theory, not a proven thing.

 

 

http://en.wikipedia.org/wiki/Gluon

 

Look on the right where it says "discovered"

Edited August 12, 2011 by questionposter

[timo]

Perhaps you are mistaking gluons for something else. It's common to take their existence as granted, and the have nothing to do with extra dimensions or "extra dimensions of folding" (by which I assume you mean small extra dimensions).

 

You can consider any particle of the Standard Model as "only theory" since the Standard Model is a theory, but that line of doing science is about as promising as "maybe reality is just an illusion". Usually, you measure processes, and when you measure a process that could not have happened in the absence of the theoretical particle then you say that the particle really exists.

[ajb]

Experimental evidence of gluons goes back a long way, 1979 is accepted as the year of discovery [1].

 

Now theoretical physics is all about building mathematical models. So it is not surprising that physicists will talk about gluons in the context of a theory (take a look at my BLOG). The best theory of particle physics is the standard model, so the context of the discussion will be here, or maybe just specialised to one sector, the QCD sector.

 

 

References

[1] PLUTO Collaboration, Physics Letters B Volume 86, Issues 3-4, 8 October 1979, Pages 418-425

[timo]

It's funny that Wikipedia cites a different article from the same journal and same volume with an almost identical title:

 

 

TASSO Collaboration: Evidence for planar events in e+e− annihilation at high energies, Physics Letters B Volume 86, Issue 2, 24 September 1979, Pages 243-249

 

Service: the article linked by ajb is called Evidence for gluon bremsstrahlung in e+e− annihilations at high energies.

[ajb]

I think there are several papers and conference proceeding from that year that all provide evidence for gluons. I don't know which, if any is considered THE paper.

[questionposter]

Experimental evidence of gluons goes back a long way, 1979 is accepted as the year of discovery [1].

 

Now theoretical physics is all about building mathematical models. So it is not surprising that physicists will talk about gluons in the context of a theory (take a look at my BLOG). The best theory of particle physics is the standard model, so the context of the discussion will be here, or maybe just specialised to one sector, the QCD sector.

 

 

References

[1] PLUTO Collaboration, Physics Letters B Volume 86, Issues 3-4, 8 October 1979, Pages 418-425

 

Ok, so I know there's kind of some experimental evidence, but is there like, proof? Like do photons actually come from a gluon in a quark gluon plasma so that we can say "hey, that's what a gluon looks like"? I can see it in the context of how we know black holes exist because we see these areas of gravitational fields where stars are sucked into something, but it seems like the only evidence for a gluon is that "there must be something holding the protons together". Or is there actual proof and its scientific fact that gluons exist? Cause there could be any number of other things holding protons together made out of forces we don't even know exist, and with the mathematical stuff, as far as I've heard, gluons occupy more than just the 4 dimensions we are familiar with. Like, did scientists observe some object which could only move in a manner that was a like, 5 dimensional object appearing in 3D space? What anomalies where there? And what about a quark gluon plasma anyway? How do they know that has gluons, which if it did, why wouldn't THAT be proof?

Edited August 12, 2011 by questionposter

[ajb]

The proof is in the fact that there are jets that are produced in high energy colliders that can only really be understood if gluons exist.

 

But is is true that no one has seen a free gluon state.

[questionposter]

The proof is in the fact that there are jets that are produced in high energy colliders that can only really be understood if gluons exist.

 

But is is true that no one has seen a free gluon state.

 

Well gluons don't carry the same charge that other particles do, so how would they warp in the path of particles like quarks which carry their own set of color chargers, especially because of confinement? With confinement, wouldn't an anti-gluon always anihilate itself? And if so, why haven't they found particles that make up the gluons when the gluons annihilate themselves? Or Since they can somehow detect them with the same chargers of other particles, why can't they create a magnetic field to repel the anti-gluon away?

Edited August 13, 2011 by questionposter

[ajb]

And if so, why haven't they found particles that make up the gluons when the gluons annihilate themselves?

 

This is very naive question. Gulons are fundamental particles, or at least to our best knowledge they are. They do not have an internal structure and so are not made up of any other particles.

 

Jets as seen in particle collides are the flurry of hardons due to the collision of heavy ions (for example). People analysed these jets using various models, like the parton model and QCD. It turns out that the best fit is achieved by using QCD and thus hadrons are understood as bound states of quarks "glued together" via gluons.

[questionposter]

This is very naive question. Gulons are fundamental particles, or at least to our best knowledge they are. They do not have an internal structure and so are not made up of any other particles.

 

Jets as seen in particle collides are the flurry of hardons due to the collision of heavy ions (for example). People analysed these jets using various models, like the parton model and QCD. It turns out that the best fit is achieved by using QCD and thus hadrons are understood as bound states of quarks "glued together" via gluons.

 

So the gluon mathematics doesn't fit perfectly, but pretty close?

[ajb]

So the gluon mathematics doesn't fit perfectly, but pretty close?

 

John Richard Ellis and collaborators back in the 1970's predicted phenomena of jets that can only occur if gluons are realised in nature. This was then experimentally confirmed in the references already given. QCD seems to fit nature well.