Multiquark states:Q3baryon resonances

The structure of the mass spectrum for orbitally and radially excited baryon resonances is explained assuming two sets of quarks in a bag, which for orbital excitations is stretched and for large $l$ values gives rise to linear trajectories. We use a phenomenological mass formula in which the dominant terms are calculated using the MIT bag model. The coupling to baryon-meson channels is determined by the creation of a quark-antiquark pair with vacuum quantum numbers.