Accurate calculation of the elastic scattering properties of 7Li atoms at ultralow temperatures

摘要

The elastic scattering properties for collisions between two 7Li atoms are investigated in the cold and ultracold regimes separately. Based on recent theoretical and experimental results, we present the improved hybrid potentials for the singlet X1∑+g N and triplet a3∑+u ground states of the Li2. Our calculated values for the scattering lengths aand the effective ranges re are compared with previous ones, and found them to be in good agreement. The scatteringlengths are 34.6ao for the singlet state and -27.6a0 for the triplet state. Shape resonances occur in the collisiona at low energies.We also calculate the total cross sectiona and the energy positions of shape resonances for both X1∑+g and a3∑+u states.