Multiquark Systems in a Constituent Quark Model with Chiral Dynamics

We discuss the stability of multiquark systems within the recent model of Glozman et al. where the chromomagnetic hyperfine interaction is replaced by pseudoscalar-meson exchange. We find that such an interaction binds a heavy tetraquark system QQq̄q̄ (Q = c, b and q = u, d) by 0.2−0.4 GeV. This is at variance with results of previous models where ccq̄q̄ is unstable. Contribution to the Workshop “Quark Confinement and the Hadron Spectrum II”, Como, Italy, June 26–29, 1996, to appear in the Proceedings, ed. Nora Brambilla, World Scientific. e-mail: [email protected] e-mail: [email protected] e-mail: [email protected] Supported by the EU Program ERBFMBICT950427 e-mail: [email protected] The baryon spectrum has recently been revisited by using chiral models which include meson-exchange forces between quarks [1, 2, 3]. A generic Hamiltonian summarising the above references reads