# Higgs boson's mechanism for giving mass?

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1. Oct 8, 2013

### keepit

What is the Higgs boson's mechanism for giving mass?

2. Oct 8, 2013

3. Oct 8, 2013

### keepit

OK, so the Higgs boson interacts with particles to give them mass (as per the previous movie) but still, does anyone know the mechanism of interaction?

4. Oct 8, 2013

5. Oct 8, 2013

### keepit

does anyone here know what the Higgs mechanism is?

6. Oct 9, 2013

### cristo

Staff Emeritus
Did you read the wikipedia page? Since you replied a minute after it was posted, I gather that you did not. If you did, what is there on that page that you do not understand?

7. Oct 9, 2013

### bapowell

To clarify: it's the interaction with the Higgs field that gives gauge particles mass. The Higgs boson is the excitation of this field.

8. Oct 9, 2013

### keepit

quite a bit actually. The wiki post and my post were only a coincidence. The math of the wiki post notwithstanding, it is really that simple?

"Don't shoot, it's only me," Bob hope 1990.

Last edited: Oct 9, 2013
9. Oct 9, 2013

### Staff: Mentor

"Simple"? It is simple if you make the model so simple that it is a very rough, and often misleading description of the actual physics.

10. Oct 9, 2013

### keepit

is the Higgs field equivalent to space itself?

11. Oct 9, 2013

### bapowell

No. It's just like any other quantum field, except that there is a property of the Higgs field that is nonzero in space.

12. Oct 9, 2013

### keepit

do the particles that are given mass by the Higgs field affect the Higgs field?

13. Oct 9, 2013

### bapowell

Yes. For example, the mass of the Higgs particle depends on all the particles to which the Higgs couples. More generally, any property of the Higgs that gets renormalized depends on all such particles.

14. Oct 9, 2013

### keepit

In general is the technique of renormalization required because of interactions?
I know the question is vague. That's because there's a lot i don't know.

15. Oct 12, 2013

### my2cts

16. Oct 12, 2013

### bapowell

That's the energy of the Higgs vacuum; I'm referring to the vacuum expectation value of the field. The latter is definitively nonzero, the former is unknown. I have no idea Veltman thinks there needs to be an energy associated with the Higgs field that would cause the universe to collapse.

17. Oct 14, 2013

### my2cts

Can you explain the difference?

18. Oct 14, 2013

### my2cts

On slide 17 of http://www.nikhef.nl/pub/theory/academiclectures/Higgs.pdf Veltman explains how he reaches this conclusion.

19. Oct 14, 2013

### my2cts

That is correct.

20. Oct 15, 2013

### bapowell

See the figure in this post: http://dorigo.wordpress.com/2007/11/10/the-goldstone-theorem-for-real-dummies/. The values +/- $\nu$ are the vacuum expectation values of the field for the corresponding vacuum. The Higgs starts in the middle, at the local maximum (the false vacuum), and rolls down to one of the minima (true vacua). The energy of the true vacua, $V(\pm \nu)$, is the vacuum energy of the Higgs. So the vacuum expectation value of the field and the vacuum energy are different things. It is generally assumed that $V(\nu)=0$, but this is really just put in by hand. If $V(\nu)<0$, then the universe should collapse if the Higgs field is dominating the energy density of the universe (this might be what Veltmann is talking about). Otherwise, if $V(\nu)>0$, the universe should inflate once the Higgs field dominates.