# Isotope Effects in Complex Scattering Lengths for He Collisions With Molecular Hydrogen

 Title: Isotope Effects in Complex Scattering Lengths for He Collisions With Molecular Hydrogen Author: Dalgarno, Alexander; Nolte, Jeff; Stancil, Phillip; Yang, B.H.; Lee, Teck-Ghee; Balakrishnan, Naduvalath; Forrey, Robert C. Note: Order does not necessarily reflect citation order of authors. Citation: Nolte, Jeff L., B.H. Yang, Phillip C. Stancil, Teck-Ghee Lee, Naduvalath Balakrishnan, Robert C. Forrey, and Alexander Dalgarno. 2010. Isotope effects in complex scattering lengths for He collisions with molecular hydrogen. Physical Review A 81(1): 014701. Full Text & Related Files: Dalgarno_IsotopeEffects.pdf (243.3Kb; PDF) Abstract: We examine the effect of theoretically varying the collision-system reduced mass in collisions of He with vibrationally excited molecular hydrogen and observe zero-energy resonances for select atomic “hydrogen” masses less than 1 u or a “helium” mass of 1.95 u. Complex scattering lengths, state-to-state vibrational quenching cross sections, and a low-energy elastic scattering resonance are all studied as a function of collision-system reduced mass. Experimental observations of these phenomena in the cold and ultracold regimes for collisions of $$^{3}$$He and $$^{4}$$He with H$$_{2}$$, HD, HT, and DT should be feasible in the near future. Published Version: doi:10.1103/PhysRevA.81.014701 Terms of Use: This article is made available under the terms and conditions applicable to Other Posted Material, as set forth at http://nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of-use#LAA Citable link to this page: http://nrs.harvard.edu/urn-3:HUL.InstRepos:5128487 Downloads of this work: