A renormalization method for three-boson system with a triboson field

Abstract

A renormalization method that introduces an auxiliary field to represent a three-body bound state is studied in a three-boson system with a triboson field. A cutoff dependence in the three-boson system emerges as a limit cycle, and the cyclic singularity is renormalized by employing two methods: a standard method and the auxiliary field method. For each method, different sets of diagrams are involved for renormalization, and thus we numerically study three quantities: counter term for renormalization, scattering length of $s$-wave boson-diboson scattering, and normalized wavefunction. We confirm that the two methods would lead to the same result.