We report on the first measurement of narrow photoassociation lines of $^{ 40}$Ca near the ${ ^3P_1}+{ ^1S_0}$ asymptote related to the molecular states $^3\Pi_u$ and $^3\Sigma^+_u$. The highly accurate binding energies and Zeeman splittings are well described by a coupled channel theoretical model, confirming theoretical predictions of long-range coefficients. Our analysis shows that only the inclusion of both energies and Zeeman splittings provides an accurate description of the long-range interaction potentials.
Categories: physics.atom-ph cond-mat.quant-gas