  The ^4He_3 bound states and the scattering of a ^4He atom off a ^4He dimer at
ultra-low energies are investigated using a hard-core version of the Faddeev
differential equations. Various realistic ^4He-^4He interactions were employed,
amomg them the LM2M2 potential by Aziz and Slaman and the recent TTY potential
by Tang, Toennies and Yiu. The ground state and the excited (Efimov) state
obtained are compared with other results. The scattering lengths and the
atom-diatom phase shifts were calculated for center of mass energies up to 2.45
mK. It was found that the LM2M2 and TTY potentials, although of quite different
structure, give practically the same bound-state and scattering results.
