Whats the difference between gluons and mesons in a nucleus??

Question

Whats the difference between gluons and mesons in a nucleus??

Answer 1

In particle physics, gluons are elementary particles that cause quarks to interact, and are indirectly responsible for the binding of protons and neutrons together in atomic nuclei.

In particle physics, a meson is a strongly interacting boson—that is, a hadron with integer spin. In the Standard Model, mesons are composite (non-elementary) particles composed of an even number of quarks and antiquarks. All known mesons are believed to consist of a quark-antiquark pair—the so-called valence quarks—plus a "sea" of virtual quark-antiquark pairs and virtual gluons.

Answer 2

Gluons mediate the strong interaction between quarks, which have a strong "charge" called color.

Mesons are quark/anti-quark pairs.  They (mostly pions) mediate the nuclear (or residual strong) interaction between nucleons.  Nucleons don't have any net color, but their component quarks do.  So nucleons can interact in sort of  the same way two neutral mollecules can interact electromagnetically.  The colorless nucleons exchange a colorless pion.

Here's a good wiki article about the nuclear interaction and how the exchange of pions can be viewed in terms of the more fundamental interaction of quarks exchanging gluons.

http://en.wikipedia.org/wiki/Nuclear_for...

Look at this diagrams in particular.  The gluons are those curly lines between the quarks.  The pion is the up and down quarks running in opposite directions between the nucleons.  The gluons are dual-colored, which allows them to mediate forces between different colored quarks.  The pion has both quark and antiquark with the same color and anti-color, so it has no net color and can mediate between the color-neutral nucleons.

http://en.wikipedia.org/wiki/Image:Pn_sc...