High accuracy photoassociation of ${}^{40}$Ca near the ${}^3{P}_1+{}^1{S}_0$ asymptote and its Zeeman effect

Abstract

We report on the first measurement of narrow photoassociation lines of ${}^{40}$Ca near the ${}^3{P}_1+{}^1{S}_0$ 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.