# What gives the Higgs boson its mass?

1. Jul 4, 2012

### Alektene

With the recent experimental evidence that the Higgs boson likely does exist, and that the Higgs field may well be responsible for "giving" mass to all matter, I am curious how we theorize what gives the Higgs particle it's own mass.

Warning: I am not a physicist so be gentle :-)

2. Jul 4, 2012

### The_Duck

The reason we need the Higgs to give mass to everything else is that nothing else in the Standard Model is ALLOWED to have mass unless we are a bit clever about it. In physicist-speak we say that adding masses for these particles in the most obvious way would violate "gauge symmetries" that are fundamental to the standard model. If these gauge symmetries are violated, the theory becomes mathematically inconsistent. So we need to explain why these particles can have mass (since we observe them to be massive) while still preserving the mathematical consistency of the underlying theory.

Thus we get clever and give mass to these particles in an indirect way, by making them interact with the Higgs field. In physicist-speak, the Higgs field "breaks electroweak gauge symmetry spontaneously." This spontaneous symmetry breaking turns out to leave us with a mathematically consistent theory of massive particles.

However, we can add a mass for the Higgs boson to the theory in the obvious way /without/ violating any gauge symmetries. Thus there's no need to explain the origin of the Higgs boson's mass--there's no mystery as to how it can be massive, and we don't need any indirect mechanism to give it mass while preserving gauge symmetries.

3. Jul 4, 2012

### Staff: Mentor

It is fine to give the leptons masses. This could be done without the Higgs. Just the bosons are problematic.

Edit: Well, I knew about the neutrino issue. Maybe I misunderstood the statement and it was quarks only.

Last edited: Jul 4, 2012
4. Jul 4, 2012

### Lapidus

No, we can not add mass terms to the electrons/muons/taus and their associated neutrinos, because then either the left SU(2) gauge symmetry or the hypercharge U(1) gauge symmetry of the theory would be broken.

These symmetries are "spontanouesly broken" by adding a Yukawa term to the Lagrangian that couples a complex Higgs doublet with the leptons. Thus via the interaction with the Higgs field the gauge symmetries are "spontanouesly broken" and the leptons gain their observed masses.

5. Jul 5, 2012

### Demystifier

Higgs interacts with itself, which gives it the mass.

6. Jul 28, 2012

### TheDemx27

So would you be able to generalize and say that the higgs is mass?

7. Jul 28, 2012

### Staff: Mentor

No. The Higgs has a mass, and it is responsible for the mass of other elementary partices. It is responsible for about 1% of the mass of all everyday matter.

8. Jul 28, 2012

### TheDemx27

I know it has a mass, but could it just be described as mass itself?

9. Jul 28, 2012

### Dickfore

No, since it carries other charges as well.

10. Jul 28, 2012

### TheDemx27

in particular, what charges?

11. Jul 28, 2012

### Dickfore

Structure of the Higgs Field

EDIT:
[STRIKE]This entry in Wikipedia is dubious and should not be trusted.[/STRIKE]

EDIT2:
Standard model Higgs sector Lagrangian
Before symmetry breaking the Lagrangian of the higgs field is:
$$\mathcal{L}_H = \left(D^{\mu}\, \varphi \right)^{\dagger} \, \left(D_{\mu} \, \varphi\right) - \frac{\lambda}{4} \, \left(\varphi^{\dagger} \, \varphi - v\right)^2$$
with the gauge covariant derivative defined as:
$$D_{\mu} \equiv \partial_{\mu} + \frac{i}{2} \, \left(g' \, Y_{W} \, B_{\mu} + g \, \vec{\tau} \cdot \vec{W}_{\mu} \right)$$
so, I guess it carries weak isospin and weak hypercharge.

Last edited: Jul 28, 2012
12. Jul 29, 2012

### Bill_K

Question: the Higgs boson is its own antiparticle. So how can it have a nonzero charge (any charge)?

13. Aug 4, 2012

### TheDemx27

Particles/Antiparticles are defined by electric charge (elementary charge). There is more than one type of charge a particle can take on.

14. Aug 4, 2012

Nonsense. Antiparticles have all charges inverted not just electric (which is in no sense elementary).

15. Aug 9, 2012

### meetbanerjee

I am a 14 year old boy and what could be a suitable answer for me for the question: What gives the Higgs boson its mass? Is it possible for an existence of another particle which gives mass to Higgs Boson? And if Higgs Boson gives mass to all the particles, from where it is gaining that property of providing mass? Does this mean that a particle originally (without Higgs Boson) has zero mass and hence the law that states- Mass cannot be zero fails? If Higgs Boson gives mass to every particle, then are we a part of this because this means that even the mass of all the celestial objects and biotic components including a microscopic cell gaining mass from Higgs Boson?

16. Aug 9, 2012

### Staff: Mentor

Higgs-bosons can interact with each other, this leads to a mass. In addition, they can directly get a mass from theory (unlike all other particles!).

Result of the calculations.

I do not know what you mean with "originally", but the basic concept is correct.

There is no such rule. And there are massless particles in nature: The photon and gluons.

To every massive particle.

No, the Higgs boson is responsible for the rest mass of particles only. Most of the mass of everyday objects (~99%) comes from binding energy in protons and neutrons.

17. Oct 21, 2013

### Superposed_Cat

I myself am a high school student (10th grade), I wonder how many minors there are on this forum.

Last edited by a moderator: Oct 31, 2013
18. Oct 22, 2013

### king vitamin

Dickfore seems to be referring to the Higgs field before spontaneous symmetry breaking, where it forms a complex doublet (so two spin-0 particle-antiparticle pairs). After SSB, it is neutral under all charges, as it must be.

And to address the Higgs needing to "give mass to itself," there exists an (extremely high) temperature where the Standard Model undergoes a phase transition, and the Higgs mechanism does not happen. In this phase, all particles are massless except for the Higgs(es), which will remain massive by themselves. I believe the Higgs should be exactly massless right at the critical temperature.

The reason fermion masses are problematic is because of the extremely important fact that the standard model is chiral; left and right handed fermions have different charges under interactions. In laymen's terms, the laws of physics look different when viewed in a mirror. However, left and right-handed fermions of the same type have the same mass. Combining these two facts is extremely constraining, and lead to the standard model.

It turns out masses are also problematic for spin-1 particles for reasons having to do with renormalizability. But spin-0 masses are not a problem (provided you don't worry about issues like naturalness/fine-tuning).

EDIT: I just noticed all but the most recent posts are over a year old, whoops, didn't realize

Last edited: Oct 22, 2013