Study On Form Factors At Effective Vertices

The diquark structure in baryons is commonly accepted as a reasonable approximation which can much simplify the picture of baryons and reduce the length of calculations. However, a diquark by no means is a point-like particle, even though it is treated as a whole object. Therefore, to apply the diquark picture to phenomenological calculations, at the effective vertices for the diquark-gauge-boson interactions, suitable form factors must be introduced to compensate the effects caused by the inner structure of the diquark. It is crucial to derive the appropriate form factors for various interactions. In this work, we use the Bethe-Salpeter equation to derive such form factors and numerically evaluate their magnitudes. Our results not only qualitatively, but also quantitatively confirm the form factors phenomenologically introduced in literature.