The use of many-body methods for the calculation of meson-like spectra

The study of properties for the low-energy regime of hadronic spectra is a challenging task; e.g. meson-like states require the introduction of effective degrees of freedom, a condition resulting from confinement. This work presents the results of adopting a non-perturbative scheme where quarks are treated as quasiparticles. These quasiparticles interact and by employing many-body techniques, we can describe a spectrum of meson-like states as a collective superposition of quasiquark-pairs followed by calculating their widths. The result of the calculations shows that this scheme is a suitable one to describe meson states up to energies of the order of a couple of GeV.