# Spin classification

1. Mar 9, 2005

### elas

From the table of particles in 'The Particle Explosion' I observe that:
Leptons and quarks have spin 1/2.
Bosons have spin 1.
Mesons, have zero spin; except for quark/antiquark pairs found by electronic detectors, that have spin 1.
Baryons of with more than one type of quark have spin 1/2. Baryons with only one type of quark have spin 3/2.
But the table only lists a small number of particles and I would like to know if there are exceptions to the above observations. (PDG does not come up in a clear readable form on my computer and I cannot find a simple 'table of particle spin').
All the articles on spin, that I have found so far, have one thing in common; very early on, they switch from interpretation and theory to theory only. It is as if, after a certain point, they are unable to explain in words exactly what the numbers mean. Indeed I get the impression that there is no agreed method of explaining spin in a non-mathematical manner. So I would be interested in any article on the subject of spin that includes a non-mathematical explanation (I appreciate that such articles must also include the mathematics).

2. Mar 10, 2005

### dextercioby

Correct.

VECTOR BOSONS have spin 1,among the fundamental particles/fields...

That's true.In quantum physics,spin is the most difficult thing to explain.My advice:learn math & read Sakurai.

Daniel.

3. Mar 10, 2005

### marlon

Bosons have integer spin, which is not necessarily equal to 1, dexter

marlon

4. Mar 10, 2005

### Hurkyl

Staff Emeritus
The problem is that SU(2) is a perversion of "real" geometry. It takes a 720 degree rotation to return any object to its starting position, not the 360 degrees it's supposed to take.

However, a spin 1 object is symmetrical -- 360 degrees is enough. It's similar to how a square is symmetrical, and only requires 90 degrees to return it to its original state. It's like a spin 4 object, except spin 4 objects can be rotated 90 degrees in any direction.

5. Mar 10, 2005

### juvenal

He did use the term "vector boson".

6. Mar 10, 2005

### dextercioby

Oh,man,u spoiled his joy... :tongue2:

Daniel.

7. Mar 10, 2005

### juvenal

Can't you Europeans get along? EU?

8. Mar 10, 2005

### dextercioby

What's EU gotta do with 2 individuals' personalities...?Nothing.

Daniel.

9. Mar 11, 2005

### elas

Thanks for the advice which I will follow, meanwhile I have been trying to get to the heart of the problem and keep hitting statements like this one from a recent paper that originated at CERN:

However it seems to us that SM is still unsatisfactory theoretically to be a truly fundamental theory.

So I would like to change the question to:

What experimental observations indicate the presence os spin?

Last edited by a moderator: Mar 11, 2005
10. Mar 11, 2005

### zefram_c

I don't know which paper that is, but I'm sure the context is more enlightening than just that quote. (Do they suggest why it is unsatisfactory, or how to improve upon it? There are valid and invalid reasons for saying that. I'm sure they don't just make that statement and move on.)

Fair enough - which particle are you interested in? For the electron, I will suggest off the top of my head the spectrum of hydrogen - complete with spin-orbit corrections, relativistic effects, Lamb shift and hyperfine splitting. I'd love to see an explanation of all those things without spin.

11. Mar 11, 2005

### juvenal

Yeah - I think spin is probably one of the least controversial topics out there.

12. Mar 11, 2005

### marlon

Still he was "wrong" :rofl: :rofl: :rofl: . Vector bosons are not the only bosons out there...

marlon

Last edited: Mar 11, 2005
13. Mar 11, 2005

### juvenal

He never made that claim. . .

14. Mar 11, 2005

### marlon

:rofl: :rofl:

Yes he did...But what do you care ?

QUOTE :
"VECTOR BOSONS have spin 1,among the fundamental particles/fields..."
/QUOTE

and what does "among the fundamental particles" mean ?

Not all bosons with spin 1 are vector bosons and they are not all fundamental.

Can't you see this ???

marlon

15. Mar 11, 2005

### dextercioby

Yes,but the statement is still correct.Vector bosons DO HAVE SPIN ONE.And vector bosons (like the gluon octet,the photon & the W+/-/0) are "AMONG FUNDAMENTAL PARTICLES"...

So how about cutting the **** out...?

Daniel.

16. Mar 11, 2005

### marlon

For the 1000th time. I did not say you were wrong, i just say you were incomplete... Please, get over it...

Nice one...Thanks...We are indeed the best of friends

marlon :zzz:

17. Mar 11, 2005

### dextercioby

Yes,u did...You edited the post and put the word wrong between " " ...But you couldn't edit Juvenal's post...In which the same word appears without the " "...

Daniel.

P.S.Marlon,who are u trying to fool...?Me???:surprised:

18. Mar 11, 2005

### marlon

Dexter, i clearly answered as to why you were WRONG in your original post. How long do i need to repeat myself ?

marlon

19. Mar 11, 2005

### dextercioby

I wasn't wrong in the original post.

Daniel.

20. Mar 11, 2005

### marlon

:rofl: :rofl: :rofl: :rofl: :rofl: :rofl:
Yes you were and i told you why...
marlon