Quark model study of the semileptonic B -> pi decay
  The semileptonic decay B->pi is studied starting from a simple quark model and taking into account the effect of the B* resonance. A novel, multiply subtracted, Omn\`es dispersion relation has been implemented to extend the predictions of the quark model to all physical q^2 values. We find |V_{ub}|=0.0034 +/- 0.0003(exp.)+/- 0.0007(theory), in good agreement with experiment. 
C. Albertus, J. M. Flynn, E. Hernandez, J. Nieves, J. M.   Verde--Velasco