Abstract
We show that an independent four-body momentum scale μ(4) drives the tetramer binding energy for fixed trimer energy (or three-body scale μ(3)) and large scattering length (a). The three- and four-body forces from the one-channel reduction of the atomic interaction near a Feshbach resonance disentangle μ(4) and μ(3). The four-body independent scale is also manifested through a family of Tjon lines, with slope given by μ(4)/μ(3) for a−1 = 0. There is the possibility of a new renormalization group limit cycle due to the new scale.