Low energy elastic scattering of H, D and T on $^{3}$He and $^{4}$He

arXiv:2601.22360v1 Announce Type: new
Abstract: Motivated by the needs of atomic tritium sources for neutrino mass experiments, we present calculations of energy-dependent elastic scattering cross sections of hydrogen isotopes (H, D and T) on helium isotopes ($^3$He and $^4$He) in the temperature range 1~mK to 300~K. The tritium-on-helium cross sections are found to be enhanced over their hydrogen-on-helium counterparts by a near-threshold resonant s-wave bound state at low energy, similar to that predicted in the triplet T-T system. While the energy-dependent cross sections span a wide range at low energy due to this s-wave enhancement, they tend toward a common value at high energy where the scattering becomes effectively geometric in nature.