High-resolution photoassociation spectroscopy of ultracold Cs₂ long-range 0_g^- state：The external well potential depth

High-resolution photoassociation spectroscopy is reported using a modulation spectroscopy technology in a cesium atomic magneto-optical trap. The two lowest vibrational levels have been experimentally observed which have been theoretically predicted in Phys. Rev. A 75 052501 (2007). A new potential curve is obtained by using the Rydberg–Klein–Ress method with a well depth of -82.384±0.026 cm^-1, which is deeper than the result of previous experiment (-77.909 cm^-1) and the theoretical prediction (-81.6445 cm^-1).