Supplemental material: Three-body-interacting bosons in free space

1 + cos2 φ). The boundary conditions for the wavefunction on the borders of the domain can be derived from Eqs. (S2-S3). The set of four equations (S4-S5) is solved numerically by using the adiabatic hyperspherical approach. Namely, we first diagonalize the hyperspherical part, i.e., we fix Π and in the kinetic energy operator (S6) we keep only the second line. We choose a grid which has many points at small θ to allow for a better accuracy at large Π. Then, we solve the coupled channel hyperradial problem keeping typically 40 hyperspherical channels. However, we find that for our parameters 10 channels is sufficient for convergence. The calculated |true3〉 is then substituted into