On the minimality of the order p^6 chiral Lagrangian

Understand

A method to find relations between the operators in the mesonic Lagrangian of Chiral Perturbation Theory at order p^6 is presented.

• The procedure can be used to establish if the basis of operators in the Lagrangian is minimal.
• As an example, we apply the method to the two-flavour case in the absence of scalar and pseudo-scalar sources (s=p=0), and conclude that the minimal Lagrangian contains 27 independent operators.