Key points are not available for this paper at this time.
The pion-pion scattering amplitudes provided by second-order chiral perturbation theory are confronted with known rigorous constraints derived from the axioms of quantum field theory. We mainly test constraints restricting the ^0^0 S- and D-wave amplitudes in the unphysical interval 04m_^2. These constraints impose significant lower bounds for a linear combination of coupling constants specifying the second-order chiral Lagrangian. The accepted value of this combination is consistent with these bounds. The ^0-^0 S and D waves are strongly correlated by a set of constraints.
Ananthanarayan et al. (Wed,) studied this question.