21. In technical terms, gluons are electromagnetic interaction but lacks an electric charge. 22. These include glueballs and hybrid mesons ( mesons bound by excited gluons ). 23. Superfluids ( like Fermionic condensate ) and the quark gluon plasma are examples. 24. Quark gluon plasma was discovered at CERN in 2000. 25. However, the gluon only holds together quarks that are three different colors. 26. This energy derives from the strong interaction, which is mediated by gluons . 27. QCD is a SU ( 3 ) gauge theory involving gluons and quarks. 28. This phase is also called the quark gluon plasma. 29. Hence free color charge and free gluons cannot exist. 30. Other vibrational modes of open strings exhibit the properties of photons and gluons .
