# Higgs field

didn't know where to post this. Was wondering earlier why objects have mass so i googled it.. i'm in grade 12 so don't really understand EVERYTHING you know lol.

but anyways found out about higgs field and higgs boson. Can someone explain how this explains why things have 'mass' like why do particles cling to it (the higgs boson) and how does this cause drag to create the mass.

stevebd1
Gold Member
I always thought the link below was a good introduction to the Higgs mechanism.

http://www.phy.uct.ac.za/courses/phy400w/particle/higgs5.htm [Broken]

regards
Steve

Last edited by a moderator:
malawi_glenn
Homework Helper
also, Higgs only explains the mass of the W and Z bosons. See the sub-forum "High Energy, Nuclear, Particle Physics", there are many threads about LHC and Higgs mechanism etc.

also, Higgs only explains the mass of the W and Z bosons. See the sub-forum "High Energy, Nuclear, Particle Physics", there are many threads about LHC and Higgs mechanism etc.

I understand it this way: Three components of the Higgs field create Electroweak Symmetry breaking and the quanta of the fourth component, the Higgs Boson gives, mass to all other fermions.

ohhh got you kind of makes more sense :D thks guys. i'll check out that article as well :D

malawi_glenn
Homework Helper
I understand it this way: Three components of the Higgs field create Electroweak Symmetry breaking and the quanta of the fourth component, the Higgs Boson gives, mass to all other fermions.

I have never herd anyone else saying this...
reference?

I understand it this way: Three components of the Higgs field create Electroweak Symmetry breaking

I would rather say the opposite. During EW symmetry breaking, 3 components of the Higgs doublet (the goldstone bosons) are eaten by W and B fields resulting in massive W and Z.

and the quanta of the fourth component, the Higgs Boson gives, mass to all other fermions.
Yes, the vacuum expectation value (vev) through yukawa terms added by hand gives mass to fermions.
So on one side these terms are added by hand.
On the other side, we cannot easily add terms like m_i e_L e_R without breaking gauge invariance.

stevebd1
Gold Member
Below is an extract from a (very) basic summary I put together some time ago regarding fermions and bosons and the Higgs mechanism-

Fermions and bosons

Informally speaking, fermions are 'stiff' and are considered to be particles of matter while bosons are considered to be carriers of the fundamental forces. Bosons have integer spin while fermions have half-integer spin. Bosons can share quantum states while fermions are constrained by the Pauli exclusion principle* and cannot.

- Fermions
As an observer circles a fermion, the wave function changes, hence the term half-integer spin (1/2, 3/2, 5/2). Fermions have an antisymmetric wavefunction and show destructive interference of identical single particle wavefunctions, hence the inability to share quantum states.
Fermions fall into 2 types, quarks (that make up protons, neutrons) and leptons (electrons, muons).

- Bosons
As an observer circles a boson, the wave function doesn't change, hence the term integer spin (0,1,2). Bosons have a symmetric wavefunction and show constructive interference of identical particle wavefunctions, hence the ability to share quantum states.
Bosons fall into 2 categories-
- gauge (or vector) bosons- which are considered elementary particles, carriers of the fundamental forces- photons (electromagnetism), W and Z bosons (weak force) and gluons (strong force).
- composite particle bosons- which include He-4 atoms (Helium with 2 protons, 2 neutrons, 2 electrons), sodium-23 atoms (11 protons, 12 neutrons, 11 electrons) and the nucleus of deuterium (1 proton, 1 neutron). These are made up of an even number of fermions (composites with an even number of fermions become bosons, while composites with an odd number of fermions remain as fermions).

There is also the Higgs boson (yet to be detected), which make up the quanta of the Higgs field. The Higgs field supposedly permeates all of space with an ocean-like ether, which has 'grain' (like that of wood) that interacts with all other particles in 3 ways (2 types for bosons, 1 type for fermions)
- photon bosons travel with the grain and are therefore light and long range.
- W & Z bosons travel 'against' the grain and are heavy and short range.
- fermions travel 'through' the grain (such as electrons and quarks which 'tumble' through the Higgs field, making them appear as matter).
The idea of grain should not be thought of as a direction in 3-dimensional space but as an abstract internal space occupied by vector bosons, quarks and electrons.

* Pauli exclusion principle, no two identical particles in a system, such as electrons or quarks can possess an identical set of quantum numbers.

Steve

I'll follow up with a seemingly dumb question here:
If the Higgs boson is the quanta for the Higgs field, and the Higgs Boson can't go faster than light, then why is a black hole even possible ?
Shouldn't the Higgs boson follow the same rules as other bosons and end up 'locked' inside the black hole ?

Some references

http://arxiv.org/abs/hep-ph/0703001" [Broken]
http://arxiv.org/abs/math/0605709" [Broken]

Last edited by a moderator:
stevebd1
Gold Member
For anyone interested, below is a link to a video of Peter Higgs talking about the Higgs mechanism-

Steve

Last edited by a moderator:
Well, still no answer on my question. Doesn't anyone see a paradox here ?
So the higgs is a particle when it's outside the black hole so it can give mass to stuff around the black hole but somehow inside, it's no longer a particle, because that's not convenient.
I'm no genius but this seems ambiguous.

Well, still no answer on my question. Doesn't anyone see a paradox here ?
So the higgs is a particle when it's outside the black hole so it can give mass to stuff around the black hole but somehow inside, it's no longer a particle, because that's not convenient.
I'm no genius but this seems ambiguous.
Do you agree that from the point of view of general relativity, there is no real paradox of "how does gravity escape a black hole ?" ?

So you are asking a question relevant in the context of quantum mechanics really. Two things :
• If you are talking about "normal mass", the Higgs is almost irrelevant. Normal mass, yours and the one of objects around you is not explained by the Higgs anyway.
• If more generally you are concerned about how anything can escape a black hole, information and in particular the photons letting you know there is charge inside and/or the gravitons letting you know there is mass and (possibly) angular momentum, or even the Hawking radiation simply, leading eventually to the complete evaporation of the black hole, no fully satisfactory answer is available as of today, since we don't know what quantum gravity is.

But we can provide you with some answers, especially you can read Beaz's stuff on virtual particles, where you can find answers to such questions as "do virtual particles travel faster than light ?" or "do they contradict relativity or causality".

So the higgs is a particle when it's outside the black hole so it can give mass to stuff around the black hole but somehow inside, it's no longer a particle, because that's not convenient.
I'm no genius but this seems ambiguous.

If I understand your question correctly: Higgs particles 'give' other particles mass. They don't []transmit[/i] gravitational force. It's a fallacy to assume that the two have to be the same thing. One assumes that the interaction between mass terms is quite seperate from the process that they originate from.

If I understand your question correctly: Higgs particles 'give' other particles mass. They don't []transmit[/i] gravitational force. It's a fallacy to assume that the two have to be the same thing. One assumes that the interaction between mass terms is quite seperate from the process that they originate from.
Once again : the Higgs boson is irrelevant to explain 99.99% of the mass we are talking about here. Normal mass around you does not come from the Higgs boson.

If you want to talk about dark matter or something like that, please state it explicitely.

somehow inside, it's no longer a particle, because that's not convenient.
BTW I did not pay enough attention to that. If someone tells you things about what is happening inside a black hole, you might as well tell him this is not science. Nobody knows what is happening behind the horizon. The horizon itself is not very special, and we don't expect that physics changes when we cross it, but we can't know.

So if I'm telling you that behind the horizon, the mass of particles is not explained by the Higgs boson or by the glue field, by nothing except little green Witten dwarfs, you can't prove me wrong.

http://arxiv.org/abs/hep-ph/0703001" [Broken]
http://arxiv.org/abs/math/0605709" [Broken]
Have those been published somewhere ?

Last edited by a moderator:
George Jones
Staff Emeritus
Gold Member
by the Higgs boson or by the glue field, by nothing except little green Witten dwarfs,

These things aren't the same?

Alright, I'm just going to hijack this thread to ask my question about the Higgs. I know it is due to a degenerate vacuum basically U|0> does not equal |0>. Could someone clearly explain multiple or degenerate vacuum states. Also, kind of related or maybe not, I was listening to a talk by Wald on QFT in curved spacetime and he said there is no way to define a unique vacuum even in the free particle case. He said this was due to a lack of time translation symmetry, so you couldn't construct a Fock space. Could someone elaborate on this and more generally on why can't construct a Fock space even for non interacting quantum gravity.

Pythagorean
Gold Member
If you are talking about "normal mass", the Higgs is almost irrelevant. Normal mass, yours and the one of objects around you is not explained by the Higgs anyway.

you and the http://math.ucr.edu/home/baez/physics/Quantum/virtual_particles.html" [Broken] you referenced both do this to me:
McIrvin said:
Furthermore, it is not at all clear that it will be useful to think of gravitational "forces," such as the one that sticks you to the earth's surface, as mediated by virtual gravitons. The notion of virtual particles mediating static forces comes from perturbation theory, and if there is one thing we know about quantum gravity, it's that the usual way of doing perturbation theory doesn't work.

you and the author seem to stop just short of denying that the Higgs Field has anything to do with our experiential mass. I've nearly completed undergraduate studies in physics and I don't think I'll see particle physics (beyond Griffith's QM) until grad school, so without further ado... specific questions:

1) Are these two (gravity and gravity) completely different mechanisms that just happen to share the same name?
2) Are these the same mechanism but in a different situation (i.e. different particles, same 'operator')?

and a possibly off-topic question

3) is what we experience as inertia described in particle physics at all?

Last edited by a moderator:
you and the author seem to stop just short of denying that the Higgs Field has anything to do with our experiential mass.
I tried to make it clear, but maybe I failed if you feel I stopped short. The Higgs field has nothing to do with our experiential mass. The Higgs mass is a missing piece of the standard model, linked to the electroweak sector. Even if quarks were massless in that (Higgs) sens, they would still have a (fairly) high constituent mass (300 MeV) inside your protons and neutrons. This is what makes you experiential mass. The mechanism producing this mass is far more interesting than the Higgs boson. It is a well defined mathematical problem with so many ramifications to such a depth that the Clay mathematical institute has put it as one of the "Millenium problems" with 1M$prize. Sorry if I can't answer the rest of your questions right now, but it would help if you could clarify them. Thanks humanino. I think you've definitely explained plenty here for me to chew on. Clearly, I don't know half of what I should. Time to go back to the books now... I tried to make it clear, but maybe I failed if you feel I stopped short. The Higgs field has nothing to do with our experiential mass. The Higgs mass is a missing piece of the standard model, linked to the electroweak sector. Even if quarks were massless in that (Higgs) sens, they would still have a (fairly) high constituent mass (300 MeV) inside your protons and neutrons. This is what makes you experiential mass. The mechanism producing this mass is far more interesting than the Higgs boson. It is a well defined mathematical problem with so many ramifications to such a depth that the Clay mathematical institute has put it as one of the "Millenium problems" with 1M$ prize.

Sorry if I can't answer the rest of your questions right now, but it would help if you could clarify them.

Hello humanino,

I have a question about this topic. If quarks were massless (gedanken experiment), then wouldn't pions be massless (goldstone bosons) ?
Thas would mean in that case we would have a composite massless particle which is not so common in our present knowledge of the world ?

Pythagorean
Gold Member
Sorry if I can't answer the rest of your questions right now, but it would help if you could clarify them.
I'm in your debt for taking the time to answer them, no apology necessary.

I guess what I'm wondering is do constituent mass and the mass imparted by the Higg's Field follow the same exact law of gravity?

And as an addendum, I was wondering if it's known where inertia fits; (i.e. if there's a separate particle proposed to be responsible for inertia, or if inertia is some consequence of conventional gravity)

Once again : the Higgs boson is irrelevant to explain 99.99% of the mass we are talking about here. Normal mass around you does not come from the Higgs boson.

I was stating this in the context of what the Higgs does, as opposed to what the Higgs does not - the point being that being responsible for certain mass terms in certain particle interactions does not in any way imply that the Higgs is responsible for transmitting the gravitational force; and still would not even if the Higgs was the origin of all mass. Therefore, invoking bits of theory about the Higgs in reference to the dynamics of black holes is not valid, because they aren't the gravitational force carriers.

I would point out that in discussions such as this, it helps to give a person benefit of the doubt when reading their opinion; just because you (collective) haven't interpreted what they were saying correctly, doesn't mean what they said was wrong. Drawing common-speech analogies in theoretical physics is fiendishly difficult and requires some suspension of disbelief if the point is to be communicated. For example:

humanino said:
If you want to talk about dark matter or something like that, please state it explicitely.

I never said any such thing. Nor did I contradict anything humanino said. The idea I intended to communicate is perfectly clear when one reads what I posted, and not what one wishes to see.