# Higgs boson and the mass of W and Z

1. Oct 2, 2008

### Unredeemed

Thanks for everyone's help so far, it's been extemely useful for researching my talk.

Whilst doing other research for my talk I came across this on wikipedia: "More specifically, the Higgs boson would explain the difference between the massless photon and the relatively massive W and Z bosons." - http://en.wikipedia.org/wiki/Higgs_boson

I know that at 10^15K electromagnetism and the weak nuclear force merge to create the electroweak force. But why does the fact that the W and Z boson are different to the photon? Surely that's simply because they're different particles? Or could the Higgs give us an incite as to what these bosons "are."

My main question is, how could the higgs boson "explain the difference between the massless photon and the relatively massive W and Z bosons."???

Thanks,
Jamie

2. Oct 2, 2008

### ZapperZ

Staff Emeritus
This question is no longer relevant to your original thread AND it is not actually "Beyond the Standard Model". It has been moved to the appropriate forum

Zz.

3. Oct 2, 2008

### Unredeemed

I thought the Higgs would have classified as BTSM.

4. Oct 2, 2008

### ZapperZ

Staff Emeritus
5. Oct 2, 2008

6. Oct 2, 2008

### hamster143

Standard Model contains a fundamental gauge symmetry SU(2)xU(1). QFT predicts that, if the symmetry is unbroken, there should be one massless particle (force mediating gauge boson) for each generator. SU(2)xU(1) has four generators, therefore there should be four particles with identical properties.

In our universe SU(2)xU(1) is somehow broken, we don't know exactly how, but Higgs is a likely breaking candidate. Higgs field interacts with four gauge bosons and turns them into a photon, Z, W+, and W-. Since the symmetry is broken, gauge bosons no longer have to be identical.

To give you a crude visual picture of what's happening. Imagine a sphere. If it's suspended in space with no gravitating objects nearby, all points on the sphere are equivalent to each other. Laws of physics are the same everywhere. A mathematician would say that the sphere is symmetric under the group of rotations which is SO(3). Any rotation can be described as a combination of rotations around three predetermined axes. (Since SO(3) has three generators) Since the symmetry is exact, you can pick any three axes you want.

If you place the same sphere inside Earth's field of gravity, it will obtain a preferred axis (towards Earth).

Last edited: Oct 2, 2008