Coon unitarity via partial waves

In this paper, we study tree-level four-point scattering amplitudes and present a novel approach to partial-wave unitarity that bypasses a lot of technical difficulties of previous approaches. In passing, we explicitly demonstrate that our approach provides a very suggestive form for the partial-wave coefficients in a natural way which is our main result. We use the Coon amplitude to exemplify this method and show how it makes important properties such as partial-wave unitarity manifest. A secondary by-product of our analysis is simple form for the partial-wave coefficients of the Coon amplitude as a single sum. Published by the American Physical Society 2024