Naive Feynman diagram question

[denni89627]

I'm far from well versed in physics, but I'm trying to understand something about a Feynman diagram I saw. The diagram shows an electron and positron annihilating, and producing a quark/anti-quark pair and a gluon. I recently saw a special on the discovery channel that said matter/anti-matter annihilation produces pure energy. Does that mean q + (-q) + gluon=E, or in other words a gluon = energy?
Dennis

 

[Parlyne]

There's really no such thing as "pure energy." The most common thing formed in particle/antiparticle annihilations is radiation - photons. However, any process is allowed provided it conserves certain quantities - energy, momentum, angular momentum, electric charge, baryon number, lepton number, color charge, and possibly other things that aren't coming to the top of my head.