The flux tube and the flux tube breaking amplitude in the harmonic approximation

In the flux tube model the amplitude for meson hadronic decay A→B+C is given by an overlap integral containing a factor γsub(bc)sup(a) which represents the amplitude that the initial flux tube a should break at a specific point, forming the two flux tubes b and c of the final two mesons. The factor γsub(bc)sup(a) is estimated in a harmonic approximation for the decays of both ordinary quark model mesons (a=flux tube ground state) and the lowest vibrational hybrids (a=first excited state of flux tube). The relationship of the flux tube model to the leading term in the evaluation of the Wilson loop expectation value is also discussed. (author)