Photoassociative Spectroscopy of ${}^{87}$Sr

We demonstrate photoassociation (PA) of ultracold fermionic ${}^{87}$Sr atoms. The binding energies of a series of molecular states on the ${}^1{\mathrm{\Sigma }}_u^{+}$ $5s^2{}^1$S${}_0+5s5p{}^1$P${}_1$ molecular potential are fit with the semiclassical LeRoy-Bernstein model, and PA resonance strengths are compared to predictions based on the known ${}^1$S${}_0{+}^1$S${}_0$ ground state potential. Similar measurements and analysis were performed for the bosonic isotopes ${}^{84}$Sr and ${}^{86}$Sr, allowing a combined analysis of the long-range portion of the excited-state potential and determination of the $5s5p{}^1$P${}_1$ atomic state lifetime of $5.20\pm 0.02$ ns. The results enable prediction of PA rates across a wide range of experimental conditions.