A SU (4) flavor symmetrical Lagrangian is constructed for the interaction of the pseudo-scalar mesons with the vector mesons. SU (4) symmetry is broken to SU (3) by suppression of terms in the Lagrangian where the interaction should be driven by charmed mesons. Chiral symmetry can be restored by setting this new SU (4) symmetry breaking parameters to zero. Unitarization in coupled channels leads to the dynamical generation of resonances. Many known axial resonances can be identified including the new controversial X(3872) and the structure found recently by Belle around 3875 MeV in the hidden charm sector. Also new resonances are predicted, some of them with exotic quantum numbers.

We discuss the mechanisms that lead to Λ(1405) production in the π − p → K 0 πΣ reaction. The problem has gained renewed interest after different works converge to the conclusion that there are two resonances around the region of 1400 MeV, rather than one, and that they couple differently to the πΣ andKN channels. We look at the dynamics of that reaction and find two mechanisms which eventually filter each one of the resonances, leading to very different shapes of the πΣ invariant mass distributions. The combination of the two mechanisms leads to a shape of this distribution compatible with the experimental measurements.

We study the interaction of the octet of vector mesons with the decuplet of baryons using Lagrangians of the hidden gauge theory for vector interactions. The unitary amplitudes in coupled channels develop poles that can be associated with some known baryonic resonances, while there are predictions for new ones at the energy frontier of the experimental research. The work offers guidelines on how to search for these resonances.

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The baryon electromagnetic form factors are expressed in terms of two-dimensional densities describing the distribution of charge and magnetization in transverse space at fixed light-front time. We calculate the transverse densities of the spin-1/2 flavor-octet baryons at peripheral distances b = O(M −1 π ) using methods of relativistic chiral effective field theory (χEFT) and dispersion analysis. The densities are represented as dispersive integrals over the imaginary parts of the form factors in the timelike region (spectral functions). The isovector spectral functions on the two-pion cut t > 4 M 2 π are calculated using relativistic χEFT including octet and decuplet baryons. The χEFT calculations are extended into the ρ meson mass region using an N/D method that incorporates the pion electromagnetic form factor data. The isoscalar spectral functions are modeled by vector meson poles. We compute the peripheral charge and magnetization densities in the octet baryon states, estimate the uncertainties, and determine the quark flavor decomposition. The approach can be extended to baryon form factors of other operators and the moments of generalized parton distributions.