Elastic collision between two H-like atoms using the ab initio static-exchange model (SEM) and a modified static-exchange model (MSEM) at cold energies are investigated in the center of mass frame considering the system as a four-body Coulomb problem where all the Coulomb interaction terms in the direct and exchange channels are treated exactly.The importance of an exact calculation to find basic physics is highlighted.In addition, the dependence of scattering length on the van der Waals interaction between the atoms and the dependence of scattering length on reduced-mass of the system are derived which is completely new information in the field of science.Elastic collision between two H-like atoms using the ab initio static-exchange model (SEM) and a modified static-exchange model (MSEM) at cold energies are investigated in the center of mass frame considering the system as a four-body Coulomb problem where all the Coulomb interaction terms in the direct and exchange channels are treated exactly.The importance of an exact calculation to find basic physics is highlighted.In addition, the dependence of scattering length on the van der Waals interaction between the atoms and the dependence of scattering length on reduced-mass of the system are derived which is completely new information in the field of science.

arXiv:1612.05728Acta Physica Polonica ANov 1, 20170 citations

Aspects of cold bosonic atoms with a large scattering length

Dongqing Zhang

Jan 1, 20061 citation

Potential energy surface of Li–O2 system for cold collisions

Piotr Szymon Żuchowski, Katarzyna Madajczyk

This paper explores the interactions between Li and oxygen in their van der Waals state for the study of cold collisions between these two species. The quartet surface was calculated using a basis set converged spin-restricted CCSD(T) method, while for the doublet state, we obtained energy splitting with respect to high-spin using both CASSCF and MRCI approaches. Our findings suggest that the interaction in the quartet state of Li–O2 is weak, with a shallow and nearly isotropic well depth of 37.5 cm−1. The shallow potential well and small reduced mass of the system allow us to predict the scattering length for all possible combinations of 6Li and 7Li with 16O2 and 17O2. This result could be useful for understanding the collision dynamics of Li-O2 in ultra-cold regime.This paper explores the interactions between Li and oxygen in their van der Waals state for the study of cold collisions between these two species. The quartet surface was calculated using a basis set converged spin-restricted CCSD(T) method, while for the doublet state, we obtained energy splitting with respect to high-spin using both CASSCF and MRCI approaches. Our findings suggest that the interaction in the quartet state of Li–O2 is weak, with a shallow and nearly isotropic well depth of 37.5 cm−1. The shallow potential well and small reduced mass of the system allow us to predict the scattering length for all possible combinations of 6Li and 7Li with 16O2 and 17O2. This result could be useful for understanding the collision dynamics of Li-O2 in ultra-cold regime.

Mar 21, 20230 citations

Dependence of the scattering length for hydrogen atoms on effective mass

M. J. Jamieson, A. S.‐C. Cheung, Henni Ouerdane

The European Physical Journal DNov 6, 200913 citations

Strong isotope effect in ultracold collision of N2+ ( ν=1 , j=0 ) with He: A case study of virtual-state scattering

Thierry Stoecklin, A. Voronin

A comparative study of the vibrational deactivation of $^{14}\mathrm{N}_{2}^{+}$ ($\ensuremath{\nu}=1$, $j=0$ ) in collision with $^{3}\mathrm{He}$ and $^{4}\mathrm{He}$ atoms is investigated. Close-coupling calculations are carried out in the ${10}^{\ensuremath{-}6}--2000\text{\ensuremath{-}}{\mathrm{cm}}^{\ensuremath{-}1}$ kinetic energy range. At very low kinetic energy, it is found that the cross sections for the collision involving $^{3}\mathrm{He}$ is strongly enhanced by the presence of a virtual state associated with the van der Waals well. The change of mass from $^{3}\mathrm{He}$ to $^{4}\mathrm{He}$ also erases a strong shape resonance at $5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ supported by the van der Waals well. As a result, the law of variation of the associated vibrational quenching rate coefficient is found to be very different for these two systems. This behavior is further analyzed by drawing the real part of the scattering length as a function of the variable mass of a fictitious He atom. Two zero energy resonances are identified for a mass of, respectively, about 3.18 and 3.85 atomic mass units.A comparative study of the vibrational deactivation of $^{14}\mathrm{N}_{2}^{+}$ ($\ensuremath{\nu}=1$, $j=0$) in collision with $^{3}\mathrm{He}$ and $^{4}\mathrm{He}$ atoms is investigated. Close-coupling calculations are carried out in the ${10}^{\ensuremath{-}6}--2000\text{\ensuremath{-}}{\mathrm{cm}}^{\ensuremath{-}1}$ kinetic energy range. At very low kinetic energy, it is found that the cross sections for the collision involving $^{3}\mathrm{He}$ is strongly enhanced by the presence of a virtual state associated with the van der Waals well. The change of mass from $^{3}\mathrm{He}$ to $^{4}\mathrm{He}$ also erases a strong shape resonance at $5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ supported by the van der Waals well. As a result, the law of variation of the associated vibrational quenching rate coefficient is found to be very different for these two systems. This behavior is further analyzed by drawing the real part of the scattering length as a function of the variable mass of a fictitious He atom. Two zero energy resonances are identified for a mass of, respectively, about 3.18 and 3.85 atomic mass units.

Physical Review AOct 26, 200534 citations

Two atoms scattering at low and cold energies

Hasi Ray

PramanaSep 13, 20146 citations

A comparative study of the vibrational deactivation of

^{14}\mathrm{N}_{2}^{+}

($\ensuremath{\nu}=1$,

j=0

) in collision with

^{3}\mathrm{He}

and

^{4}\mathrm{He}

atoms is investigated. Close-coupling calculations are carried out in the ${10}^{\ensuremath{-}6}--2000\text{\ensuremath{-}}{\mathrm{cm}}^{\ensuremath{-}1}$ kinetic energy range. At very low kinetic energy, it is found that the cross sections for the collision involving

^{3}\mathrm{He}

is strongly enhanced by the presence of a virtual state associated with the van der Waals well. The change of mass from

^{3}\mathrm{He}

^{4}\mathrm{He}

also erases a strong shape resonance at $5\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$ supported by the van der Waals well. As a result, the law of variation of the associated vibrational quenching rate coefficient is found to be very different for these two systems. This behavior is further analyzed by drawing the real part of the scattering length as a function of the variable mass of a fictitious He atom. Two zero energy resonances are identified for a mass of, respectively, about 3.18 and 3.85 atomic mass units.