# Meson, Baryon

1. Jul 2, 2012

### Flavia

Mesons are bosons, while the baryons are fermions.

My question is, meson is a type of hadron that made from the interaction of quark with gluon. Quark is fermion, not boson. so why mesons are boson?

2. Jul 2, 2012

### tensor33

Bosons are particles with integer spin. Each quark has a half integer spin. When the quarks combine to form mesons and baryons, their spin numbers add together. Because there are two quarks in a meson, their spins add up do an integer spin, making it a boson.

3. Jul 2, 2012

### Jimmy

Whether a particle is considered a fermion or boson depends on its spin. Composite particles such as mesons and helium-4 atoms are considered bosons because they contain an even number of fermions and thus have integer spin. This is in contrast to particles such as protons, neutrons, and helium-3 atoms which contain an odd number of fermions and have half-integer spin.

http://hyperphysics.phy-astr.gsu.edu/hbase/particles/spinc.html