A Theory of Scalar Mesons
Abstract
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-qbar states. Comparing with previous work where the q-qbar 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-qbar states (dominating in the heavier mesons) emerges.
Cite
@article{arxiv.0801.2288,
title = {A Theory of Scalar Mesons},
author = {G. 't Hooft and G. Isidori and L. Maiani and A. D. Polosa and V. Riquer},
journal= {arXiv preprint arXiv:0801.2288},
year = {2008}
}
Comments
10 pages, 2 figures. References added. Presentation improved. Unchanged in substance. To appear in Phys Lett B