Physical-Region Constraints on Low-Energy Partial-Wave Amplitudes. II.ππScattering

Abstract

Physical-region constraints on the low partial waves of $\pi \pi$ scattering are derived on the basis of analyticity, crossing, and positivity of the absorptive parts. These constraints are sensitive only to the low-energy behavior of the partial-wave amplitudes. The necessity for subtractions in the dispersion relations implies that no results can be obtained for $s$ and $p$ waves.