Semi-relativistic potential model for low-lying three-gluon glueballs

por Mathieu Vincent (UNiversite de Mons-Hainaut, Belgium)

viernes 15 dic. 2006 12:00 → 13:00 Europe/Madrid

Sala Seminarios (Dpto. de Física Teórica (UVEG))

The Quantum Chromodynamic (QCD) is the modern theory of the strong interaction. The QCD allows the coupling of gluons, the gauge particles of the interaction, which can in theory form a observable state. These bound states of gluons are called glueballs. The glueballs haven't been observed yet but it seems that they mix strongly with the light mesons in observed states. The glueballs spectrum deserved interest for the understanding of such exotic system. We propose to study the spectrum of the three-gluon glueballs from the point of view of the potential models. In this approach, the spectrum is given by the eigenvalues of a Hamiltonian. This Hamiltonian is the sum of a semi-relativistic kinetic operator and a potential. In QCD, the potential is given by the sum of a perturbative part arising from a non relativistic reduction of Feynman diagrams at lower order and a confining potential simuling the non perturbative part of the interaction. We consider effective gluons with a mass given by the confinement and with a size to avoid problems induced by the perturbative part of the potential. The Hamiltonian depends on three parameters : the strong coupling constant, the string tension and the gluon size. These parameters was fitted on the two-gluon glueballs. Our spectrum for the three-gluon glueballs are in good agreement with the lattice results. [V.~Mathieu, C.~Semay and B.~Silvestre-Brac, Phys.\ Rev.\ D {\bf 74} (2006) 054002 hep-ph/0605205]