Interaction potentials for the X $^{1}\mathrm{\ensuremath{\Sigma}}_{\mathrm{g}}^{+}$ and a $^{3}\mathrm{\ensuremath{\Sigma}}_{\mathrm{u}}^{+}$ states of ${\mathrm{Na}}_{2}$ are constructed and used in calculations of the elastic scattering of two Na atoms at ultralow temperatures. The sensitivity to retardation effects (or Casimir corrections) is explored. The calculated elastic and spin-change cross sections are very large, of the order of ${10}^{\mathrm{\ensuremath{-}}12}$--${10}^{\mathrm{\ensuremath{-}}13}$ ${\mathrm{cm}}^{2}$ at zero temperature. The predicted scattering lengths are both positive, 34.9 ${\mathit{a}}_{0}$ for the X $^{1}\mathrm{\ensuremath{\Sigma}}_{\mathrm{g}}^{+}$ state and 77.3 ${\mathit{a}}_{0}$ for the a $^{3}\mathrm{\ensuremath{\Sigma}}_{\mathrm{u}}^{+}$ state. Pronounced shape resonances appear for the l=3 and 7 partial waves for the singlet and l=6 for the triplet states.Interaction potentials for the X $^{1}\mathrm{\ensuremath{\Sigma}}_{\mathrm{g}}^{+}$ and a $^{3}\mathrm{\ensuremath{\Sigma}}_{\mathrm{u}}^{+}$ states of ${\mathrm{Na}}_{2}$ are constructed and used in calculations of the elastic scattering of two Na atoms at ultralow temperatures. The sensitivity to retardation effects (or Casimir corrections) is explored. The calculated elastic and spin-change cross sections are very large, of the order of ${10}^{\mathrm{\ensuremath{-}}12}$--${10}^{\mathrm{\ensuremath{-}}13}$ ${\mathrm{cm}}^{2}$ at zero temperature. The predicted scattering lengths are both positive, 34.9 ${\mathit{a}}_{0}$ for the X $^{1}\mathrm{\ensuremath{\Sigma}}_{\mathrm{g}}^{+}$ state and 77.3 ${\mathit{a}}_{0}$ for the a $^{3}\mathrm{\ensuremath{\Sigma}}_{\mathrm{u}}^{+}$ state. Pronounced shape resonances appear for the l=3 and 7 partial waves for the singlet and l=6 for the triplet states.

Physical Review ADec 1, 1994102 citations

Light scattering from excited hydrogen atoms

L. Vriens

Physics Letters AJan 1, 19766 citations

Low energy elastic scattering of hydrogen, deuterium, and tritium on helium isotopes

B. J. P. Jones, A. Negi, Aleksei Semakin

Abstract Motivated by the needs of atomic tritium sources for neutrino mass experiments and Doppler-free two-photon 1 S–2 S spectroscopy in atomic deuterium and tritium, 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 one that has been 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.Abstract Motivated by the needs of atomic tritium sources for neutrino mass experiments and Doppler-free two-photon 1 S–2 S spectroscopy in atomic deuterium and tritium, 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 one that has been 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.

arXiv:2601.22360The European Physical Journal DAug 1, 20260 citations

Interaction potentials for the X $^{1}\mathrm{\ensuremath{\Sigma}}_{\mathrm{g}}^{+}$ and a $^{3}\mathrm{\ensuremath{\Sigma}}_{\mathrm{u}}^{+}$ states of

{\mathrm{Na}}_{2}

are constructed and used in calculations of the elastic scattering of two Na atoms at ultralow temperatures. The sensitivity to retardation effects (or Casimir corrections) is explored. The calculated elastic and spin-change cross sections are very large, of the order of ${10}^{\mathrm{\ensuremath{-}}12}$--${10}^{\mathrm{\ensuremath{-}}13}$

{\mathrm{cm}}^{2}

at zero temperature. The predicted scattering lengths are both positive, 34.9

{\mathit{a}}_{0}

for the X $^{1}\mathrm{\ensuremath{\Sigma}}_{\mathrm{g}}^{+}$ state and 77.3

{\mathit{a}}_{0}

for the a $^{3}\mathrm{\ensuremath{\Sigma}}_{\mathrm{u}}^{+}$ state. Pronounced shape resonances appear for the l=3 and 7 partial waves for the singlet and l=6 for the triplet states.