Renormalization of the f0(980) and a0(980) scalar resonances in a   nuclear medium
  The meson meson interaction in the scalar sector in the presence of a nuclear medium is studied with particular attention to the change of the properties of the f0(980) and a0(980) resonances. By using a chiral unitary approach which generates the f0 and a0 resonances and reproduces their free properties, we find that the position of the resonances in the medium is barely changed but their widths are considerably broadened. New many body corrections generating from higher orders in the chiral Lagrangian plus the contribution from N*h excitations, not considered before in connection with the pion-pion interaction in the nuclear medium, are also investigated. 
E. Oset, M.J. Vicente Vacas