Pion transition form factor in the constituent quark model

Understand

We calculate the transition form factor of the neutral pion where one photon is virtual and another photon is real in the model where the light constituent quark mass and the quark-pion vertex are taken to be momentum independent.

• Radiative corrections to the lowest order triangle quark Feynman amplitude are calculated.
• The resummation of the lowest radiative corrections to the virtual photon vertex is done by applying the Sudakov exponential hypothesis.
• Using fitting parameters, the quark mass and the strong coupling constant, the results on the pion transition form factor are compared with existing data published by CELLO, CLEO, BaBar and Belle collaborations.