“…An important point, which seems not to be fully appreciated in previous studies, is that the emergent low-energy parameter r * j is defined only up to multiplicative factors of e π/γ , i.e., e nπ/γ r * j with n being an arbitrary integer corresponds to the same physics. As a consequence, each supercritical channel exhibits the discrete scale invariance, which also emerges in nonrelativistic one-body [25], two-body [27], and three-body [28] problems and can be viewed as a manifestation of the quantum scale anomaly and the renormalization group limit cycle [29,30].…”