Multi-particle Interpolating Operators in Quantum Field Theories with Cubic Symmetry

Numerical studies of lattice quantum field theories are conducted in finitespatial volumes, typically with cubic symmetry in the spatial coordinates.Motivated by these studies, this work presents a general algorithm to constructmulti-particle interpolating operators for quantum field theories with cubicsymmetry. The algorithm automates the block diagonalization required to combinemultiple operators of definite linear momentum into irreducible representationsof the appropriate little group. Examples are given for distinguishable andindistinguishable particles including cases with both zero and non-zero spin.An implementation of the algorithm is publicly available athttps://github.com/latticeqcdtools/mhi.