Johan Bijnens, Nils Hermansson-Truedsson, Si Wang
The order p^8 mesonic chiral Lagrangian
Abstract
We derive the chiral Lagrangian at next-to-next-to-next-to-leading order (NNNLO) for a general number N_f of light quark flavours as well as for N_f=2,3. We enumerate the contact terms separately. We also discuss the cases where some of the external fields are not included. An example of a choice of Lagrangian is given in the supplementary material.
