The ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ binding energy and the $n$-${}_{}{}^3{}_{}{}^{}\mathrm{H}$ and $p$-${}_{}{}^3{}_{}{}^{}\mathrm{H}$ phase shifts below the $d+d$ threshold are calculated from Alt-Grassberger-Sandhas equations taking into account the full subamplitudes. As two-body interaction a separable $s$-wave spin-dependent potential is used.

• Received 30 November 1977

DOI:https://doi.org/10.1103/PhysRevLett.40.834