# Is the graviton a different particle from the higgs boson

1. Jul 12, 2010

### filegraphy

I was reading this book that separated the graviton from the higgs boson. Can I get some help anything works for me.

2. Jul 12, 2010

### jimgraber

Well, to start, the graviton is spin 2, the Higgs is spin 0.
Then, the graviton is massless, the Higgs (if it exists) is very massive, much more than a proton.
Third, very roughly speaking, the graviton transmits gravitational force,
the Higgs field (related to the Higgs particle) creates or generates the masses in all other massive particles.
All of the above is a little to a lot oversimplified.
Best,
Jim Graber

3. Jul 13, 2010

### kaksmet

To simplify the above further, yes it is two completely different particles. performing two entirely different parts in particle physics.

4. Jul 13, 2010

### filegraphy

So would the Higgs boson be a force carrying particle even if it were massive? What is the function of the Higgs boson? Is the graviton the force carrying particle for gravity?

5. Jul 13, 2010

### blechman

The Higgs boson would mediate a force of sorts, but no one gives it a name. It's just part of the "Electroweak Force". Its force is similar to that of the "Z boson" (with some technical differences).

And yes, the "graviton" is the particle that mediates the gravitational force.

6. Jul 13, 2010

### tom.stoer

The Higgs field is "decomposed" into two parts
a) a constant, non-fluctuating classical vacuum expectation value responsible for the masses of W, Z and the fermions
b) the fluctuations around this vacuum expectation value which appear as Higgs bosons carrying a kind of "force" (as blechman said)

7. Jul 13, 2010

### Naty1

They are certainly two separate and different theoretical particles; neither has been proved experimentally. There is hope that the Large Hadron Collider may confirm the existence of the Higgs boson. The Higgs boson is I think the only standard model particle that has not been detected experimentally; gravity is not part of the standard model.

8. Jul 13, 2010

### nismaratwork

I would add that the Higgs Boson is not required, just the Higgs Mechanism, and as Naty1 pointed out, there is no evidence of it, and certainly no evidence of gravitons. The Higgs would be nice to find however...

9. Jul 14, 2010

### tom.stoer

Some further remarks:

As nismaratwork said the particle itself is not so relevant, the mechanism of spontaneous breaking of the electro-weak gauge symmetry is what matters. Unfortunately there are no fully viable Higgs-less alternatives, but the community is working on them, just to have a fallback strategy if the LJC disproves the existence of the Higgs.

One must distinguish gravitons and gravitational waves. The latter one are required by GR and there are indirect results indicating their existence. Gravitons are theoretical artefacts based on analogies between quantizing the electromagnetic field (which gives us the photon) and quantizing the gravitational field. It could work that way, but it is also possible that quantizing gravity is totally different from quantizing other fields; therefore this does not necessarily mean that the graviton is required by nature.

10. Jul 14, 2010

### filegraphy

So if the Higgs boson were massive, following relativity, it would be a force carrying particle traveling the speed of light causing it to have infinite mass. I thought a massive object cannot travel at the speed of light or else it would have infinite mass. Something is wrong with this picture.

11. Jul 14, 2010

### the_house

Force carrying particles do not necessarily travel at the speed of light. Just like any other type of particle, that's only if they're massless.

12. Jul 14, 2010

### blechman

particles traveling at the speed of light do not have infinite mass!! you're think of the old and antiquated idea of "relativistic mass" which we no longer use. whenever we refer to "mass" we always mean "rest mass", that is, the energy of the particle when it's at rest:

$$E^2=p^2c^2 + m^2c^4$$

So mass is the amount of energy the particle has when p=0.

You can prove that when the mass vanishes (in the sense I am saying here), then the particle is traveling at the speed of light (think photon!). When the mass does NOT vanish, you can prove that it would take an infinite amount of energy to get the particle's velocity up to the speed of light. That's where the "infinite energy" comes in.

13. Jul 14, 2010

### blechman

also, what he said!!

14. Jul 14, 2010

### filegraphy

So the Higgs boson is a massive force carrying particle. It travels less than the speed of light. what force or energy does it carry?

15. Jul 14, 2010

### blechman

as i said above, it carried a force similar to the force carried by the Z boson. It doesn't have a name, it's just lumped into the "Electroweak force"

16. Jul 14, 2010

### tom.stoer

The Higgs can turn fermion species into each other; or it can mediate fermion-antifermion annihilation into gauge bosons.

17. Jul 15, 2010

### filegraphy

So how are we able to combine the photon (electromagnetic force) with the W and Z bosons (weak nuclear force). Would this create the Higgs boson.

18. Jul 15, 2010

### tom.stoer

No.

The simplest way to understand how particles interact with each other is to look at the Feynman diagrams. You will see that there is no direct interaction between the photon and the Higgs (no photon-Higgs-vertex).

19. Jul 15, 2010

### diggy

In principle yes, but its possible you are asking if Santa and the Easter bunny are different people.

20. Jul 15, 2010

### filegraphy

Ok thanks. This is making a little more sense now. I appreciate it.