Glueball phenomenology and the relativistic flux tube model

The relativistic flux tube model is an effective description of confined quarks and gluons derived from QCD. It is not a potential approach since the confining interaction is carried by the flux tube, a Nambu-Goto string. We first show that the relativistic flux tube model can be applied to glueballs seen as bound states of transverse constituent gluons. After a comparison of that approach to usual spinless Salpeter Hamiltonians, we compute glueball masses and decay widths. Comments about the η-η′-pseudosclar glueball problem, the glueball–Pomeron conjecture, and finite-temperature effects are finally given. We also point out the existence of a duality between openand closed-flux tube models of glueballs.