A theory of scalar mesons

作者：'t Hooft G; Isidori G; Maiani L; Polosa A D^*; Riquer V

来源：Physics Letters B, 2008, 662(5): 424-430.

DOI：10.1016/j.physletb.2008.03.036

We discuss the effect of the instanton induced, six-fermion effective Lagrangian on the decays of the lightest scalar mesons in the diquark-antidiquark picture. This addition allows for a remarkably good description of light scalar meson decays. The same effective Lagrangian produces a mixing of the lightest scalars with the positive parity q (q) over bar states. Comparing with previous work where the q (q) over bar mesons are identified with the nonet at 1200-1700 MeV, we find that the mixing required to fit the mass spectrum is in good agreement with the instanton coupling obtained from light scalar decays. A coherent picture of scalar mesons as a mixture of tetraquark states (dominating in the lightest mesons) and heavy q (q) over bar states (dominating in the heavier mesons) emerges.

• 出版日期2008-5-8