# Why carrying force particles must be bosons?

1. Jul 9, 2012

### ndung200790

I have not seen in any book explain why carrying interaction particles must be boson particles.Please teach me this.

2. Jul 10, 2012

### ndung200790

I do not understand why there is possibly to exist many particles of carrying force field at the same energy,so that we conclude the carrying force particles must be bosons(that obey Bose-Einstein statistic)

3. Jul 10, 2012

### ndung200790

Now,I think that it is because the force is additive,so that there are many particles of carrying force.Is that correct?

4. Jul 10, 2012

### fzero

If you're referring to gauge interactions, then gauging a bosonic symmetry will always lead to a bosonic gauge field, since the covariant derivative must have the same statistics as the field it's acting on.

It's possible to write down interactions between fermions without any gauge fields, like the four-fermion terms $(\bar{\psi}\psi)(\bar{\chi}\chi)$, but these are nonrenormalizable.

5. Jul 10, 2012

### ndung200790

Please say what is ''bosonic symmetry''.Are SU(2)xU(1) and SU(3) being bosonic symmetry?

6. Jul 10, 2012

### fzero

By bosonic symmetry, I mean the familiar type of transformation where the parameter is a c-number. A fermionic symmetry would have a parameter that is a Grassmann number, such as in BRST or supersymmetry transformations.