The sigma and f_0(980) from K_e4+pi-pi, gamma-gamma scatterings, J/psi, phi to gamma sigma_B and D_s to l nu sigma_B
arXiv:1009.3590 · doi:10.1016/j.nuclphysbps.2010.10.046
Abstract
We extract the pole positions, hadronic and gamma-gamma widths of sigma and f_0(980, from pi-pi and gamma-gamma scattering data using an improved analytic K-matrix model. Our results favour a large gluon component for the sigma and a \bar ss or/and gluon component for the f_0(980) but neither a large four-quark nor a molecule component. Gluonium sigma_B production from J/psi, phi radiative and D_s semi-leptonic decays are also discussed.
4 pages, 5 figures, 6 tables, talk given by X.-G. Wang at QCD 10 (25th anniversary) 28th june-2nd july 2010 (Montpellier - FR)