Higgs Boson Vs. Graviton

rezza

Hi.

I hope I'm posting in the right place. I was just wondering, what is the difference between the graviton and the higgs boson. I'm not quite sure, I think I sort of understand it... but not really.

Also, since I don't want to make a new thread for such a small question, is there anything known about the curvature of the 11th dimension in M-theory? Is there even such a thing for a dimension so small? Does it matter?

Norman

The higgs boson is the field that interacts with particles to give them mass. Think about it as the answer to the question: Where does mass come from? The answer is: from the interaction between the particle and the higgs field.

The graviton, is the theoretically predicted quanta of the gravitational field. If a quantum field theory of gravity exists, the graviton would be the particle which mediates the gravitational force much like the photon for QED.

I am not comfortable with string theory so I will leave that to someone else.
Cheers

arivero

Now you mention it, it is puzzling. If you hear the typical mantra "tell me a even spin particle whose couplings are proportional to the masses of the particles it couples to", then the answer should be the graviton, shouldn't be ?

ohwilleke

Gravitons need to be spin 2 since they interact with photons. Higgs can be spin 0, because they do not.

arivero

Another difference is that the Higgs boson is massive. Thus, joining this to ohwilleke remark (are we sure photons do not couple to the Higgs? and Z and W?), we have that Higgs "-gravity" is short range and only (mostly?) between fermions.

yourdadonapogostick

how can Higgs be massive if it is what causes mass?

ZapperZ

The Higgs gives particle the property of mass. Once the particle has mass, it eminates a gravitational field. The gravitons are the mediator of this gravitational interaction.

Think of it this way. If we ever find that the charge on particles is caused by a similar gauge boson (let's call it "chargon" although that name has been used before), then these chargons give particles the net charge we observe. Once a particle has a net charge, then this particle will give off EM fields that are mediated by photons.

So in this example, the chargons are like the Higgs, while the gravitons are like the photons.

Zz.

Nereid

And a (belated) welcome to Physics Forums, rezza!

What a great question to start your 'life' with PF.

marlon

yes, at least not via spontaneous breakdown of gauge symmetry

marlon

marlon

Look the Higgs is a postulated particle. It was born as a mathematical trick in order to solve some problems concerning symmetry in quantum field theory. The Higgs has mass because we defined it like that. The Higgs particle gives mass to elementary particles via it's interaction with these particles. This interaction can be expressed in terms of a coupling between the higgs field and the elementary particle field. The coefficient of the product of these fields is the mass of the elementary particle. This is just how the QFT formalism works. This is all very nice but the question remains as to wether this is true. This is why many scientists await the first experimental verification of this system of spontaneous breakdown and mass generation. Also, elementary particles need to be massless when in gauge theory because of symmetry reasons. I have written many topics on this in my journal, go check it out

search for the entries on the Higgs field and 'why elementary particles are massless'

This is very interesting stuff but not that easy.
Also i read analogy stuff like 'the gravitons are the photons'. Do not pay any attention to this because it is fundamentally wrong. Gravitons are very different in nature, they indeed mediate the gravitational force but they are different in nature because they ARE particles of space time itself. There is not such a think as gravitational radiation or some sort. If this were the case, the analogy with photons is justified. Keep this in mind...


regards
marlon

Scroll down to the Higgs field entry and read why elementary particles are massless on the next page (8)
http://www.physicsforums.com/journal...page=10&page=9

peebeebaynut

Was the smallness of the secondary question the only reason you bundled it? Or are you telling us something about the relationship between the two questions?

Curvature of the 11^th dimension in M-theory? Well the first four dimensions set the precedent, so I can't imagine other dimensions could not follow it.

But how does the structure of the 11^th dimension in M-theory convey mass and/or gravity and/or influence the Higgs Boson vs. graviton is something I can't yet answer.

Regards.

humanino

How about : the two chiral components live in different sheets and what we call Higgs connects them ?

bfollinprm

This really frustrates me as well. Relativity tells us that inertial and gravitational masses are the same thing (that's central to the theory). So, why is it that we need a separate Higgs (inertial) field and gravitational field?

ZapperZ

But this is one of those things that we have to continue to verify. We still check if "c" is a constant and anisotropic. Just because Relativity say it is so, doesn't mean we do not continue to test it to greater precision!

Because A causes B, and in turn, B causes C.

Higgs field endows a particle with mass, and that mass in turn is the origin of gravity! They are not the same thing!

Not sure why this thread continually gets resurrected after a period of being dormant.

Zz.

JustinLevy

I think the problem here is the gross oversimplification that "Higgs causes mass". The rest energy of a system is the mass of that system.

Consider the proton. Yes, some mass comes from interaction with the Higgs, but the vast majority comes from interactions mediated by gluons.

Gravity couples to the stress energy tensor. For the equivalence principle to hold, it can't "care" what the different contributions to the stress energy tensor are. And the Higgs is not the sole contributor let alone a major contributor, so it is not the cause of gravity, nor really even a real big cause of the 'source' of gravity.

---

For those QFT savy, would it be correct to say that with a non-zero vaccuum expectation of the Higgs, it is a redefinition of the fields (of massless fermions) to include these interactions which yields the "massive" fermion fields? ie. that the fermions are still massless per se, it is just mathematically convenient to subsume this interaction into the definition of the field? Am I even close?

Frame Dragger

As Marlon said: The Higgs MECHANISM gives rise to mass, and that could be the case with, OR without an actual Higgs Boson.

@JustinLevy: The SET describes the curvature we call gravity... it doesn't impart the mass which acts on the SET in the first place. That's why it's important to distinguish the idea of a specific REAL particle, vs. the mechanism which is what is really being discussed.

Naty1

"I was just wondering, what is the difference between the graviton and the higgs boson."

As was posted above, great first question. Lots to learn here!!!!

On the other hand don't think that "spin 2" etc will explain much because gravitons are attempts to explain a mathematical result as a physical entity. Sometimes such explanations seem to "explain" things, most of the time we have more math than fits our universe. In other words, even Einstein had some difficulty deciding which mathematical formulation for general relativity would be best to use...he had several and had to discard most......it was the "equivalence principle" which led him to be able to guess which one might match experimental results. "spin two" was an "accidental" discovery hiding within string theory when it was discovered.

Nobody even knows if gravitons exist, and if they do, where they came from, where they are going, and whether they might survive a grand unification theory (combining quantum mechanics and general relativity). All particles and energy may result from spontaneous symmetry breaking; that's the best theory we seem to have currently. But in fact nobody knows for sure what any particle "is" (Exactly what is an "electron" for instance) maybe a "string"?? Maybe a probability wavefunction) , nor what time, space, and gravity actually are. What we do have are some neat theories that make predictions and to the extent we can test them experimentally seem to work pretty well.

It's good to keep in mind things (the world around us) are very deceiving: are you the "same" person you were a year or two ago?? Not really, just about every cell in your body has been replaced!!! Our five senses are narrowband filters that keep out 99.9% of what is around us so we are easily mislead. Somehow,though, our brain has developed beyond our meager senses..so we are able contemplate "gravitons" even though we cannot sense them.