A three-body force model for the baryon spectrum

We present a theoretical approach to the internal baryon structure based on three-body forces among quarks. Using three-body potentials, one can both include the current two-body potential models (in an effective way) and investigate new dynamical mechanisms. The spin-independent part of the interaction is assumed to be hypercentral and treated using the hyperspherical harmonic formalism, leading to a level scheme reproducing qualitatively the observed pattern of the spectrum. We discuss some results obtained using a potential with a (mostly linear) confinement part and some inverse power terms; however the potential can be easily generalized in order to allow a systematic analysis. Adding the hyperfine interaction, which is diagonalized directly in the basis states, the spectrum can be fairly reproduced. The compatibility of the spectrum and the change form factor is briefly discussed.