The ~U(12)-Classification Scheme, Static U(4)-Spin Symmetry for Light-Quarks and "Exotic" Hadrons

Abstract

Several years ago we have proposed a manifestly covariant $\tilde{U}(12{)}_{SF}$-classification scheme of hadrons, which maintains the successful $SU(6{)}_{SF}\otimes O(3{)}_L$ framework in Non-Relativistic Quark Model and is also reconcilable with the mechanism of Spontaneously-Broken Chiral Symmetry in Relativistic Field Theoretical Models. The essential point here is to notice the overlooked freedom of the $SU(2{)}_{\rho }$-spin for (confined) light quarks, which leads to existence of new type of ``exotic'' hadrons, called ``chiralons'' and to a selection rule, ${\rho }_3$-line rule, on the spectator quark line. A series of puzzling new hadrons recently observed such as X(3872)-meson family and $\Theta (1540)$ and so on are possibly classified mostly as chiralons.

Nov 2005. 5pp. To appear in the proceedings of the 11th International Conference on Hadron Spectroscopy (Hadron05), Rio de Janeiro, Brazil, 21-26 Aug 2005