Neutron-H3and Proton-H3eZero Energy Scattering

The Kohn variational principle and the (correlated) hyperspherical harmonics technique are applied to study the $n{-}^3\mathrm{H}$ and $p{-}^3\mathrm{He}$ scattering at zero energy. Predictions for the singlet and triplet scattering lengths are obtained for nonrelativistic nuclear Hamiltonians including two- and three-body potentials. The calculated $n{-}^3\mathrm{H}$ total cross section agrees well with the measured value, while some small discrepancy is found for the coherent scattering length. For the $p{-}^3\mathrm{He}$ channel, the calculated scattering lengths are in reasonable agreement with the values extrapolated from the measurements made above 1 MeV.