# What is a boson?

1. Jul 14, 2009

### dayan83

Can anyone provide a basic explanation what a boson is? I am not very familiar with quantum physics, so couldn't find an understandable explanation in the web.

Thanks!

2. Jul 14, 2009

### haushofer

From experiments we know that particles have some sort of "intrinsic rotation", called spin. This is a fixed characteristic of a particle, just like its mass. Now, it seems that particles with half integer spin (1/2,3/2 etc) are called Fermions and they behave quite differently from particles with integer spin (0,1,2 etc) which are called Bosons. People also say that they behave under different statistics: Bosons don't have any problem being close to eachother, while Fermions have big problems with this. This is called the spin-statistics theorem.

An example of Bosons are the force-carriers. Forces are in the quantumformalism described by the exchange of virtual particles, and these particles are bosons. (the reason for this is mathematical, and has to do with the way people introduce these so-called gaugings).

Another example is the meson, which consists of a quark and an antiquark. Quarks are Fermions with spin 1/2, but if you have two quarks together in a bound state you get a Boson (roughly, because 1/2 and 1/2 can only "add up" to an integer).

I hope I was useful, but I'm sure many more people can say something about this :)

3. Jul 14, 2009

### clem

A boson is any particle that satisfies "Bose-Einstein" statistics.
That is, the wave function of a number of identical bosons must be symmetric with respect to any interchanges of particles.

4. Jul 14, 2009

### Tac-Tics

All particles are divided into two types: bosons and fermions.

Bosons are things like photons. They tend to clump together. Their properties are important for lasers to work. Super cold Helium-4 is also a boson, even though it is matter, and acts in very interesting ways that normal matter doesn't.

Fermions are things like protons, electrons, and electrons. They tend to isolate from one another. The most familiar name for this is the Pauli Exclusion principle. This is what keeps atoms from imploding.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook