We treat low-energy $^3$He-$\alpha$ elastic scattering in an Effective Field Theory (EFT) that exploits the separation of scales this reaction. compute amplitude up to Next-to-Next-to-Leading Order (NNLO), developing a hierarchy effective-range parameters contribute at various orders. use resulting formalism analyze data for recent measurements center-of-mass energies 0.38-3.12 MeV using SONIK ...
