π → lνγ form factors at two-loop

J. Bijnens, P Talavera
1997 Nuclear Physics B  
Within Chiral Perturbation Theory (CHPT) we compute the form factors A, V and $\gamma = A/V$ in the $\pi \to \nu l \gamma$ decay to $O(p^6)$. A and $\gamma$ obtain corrections of order 25%.
doi:10.1016/s0550-3213(97)00069-2 fatcat:jrllh45s2ret5ncs25ocqhj7sm