New observation and analysis of the ultracold Cs 2 0 u + and 1 g long-range states at the asymptote 6S 1/2 +6P 1/2

Photoassociation of ultracold Cs atoms is reported in magneto-optical trap with the modulation technique. Trap loss spectroscopy of the ultracold Cs2 molecules has been obtained experimentally. Spectroscopy data are expended to the red detuned of 70 cm-1 below the 6S1/2+6P1/2 dissociation limit. Several new low lying vibrational levels belongs to the 0u+ and 1g states are identified and analyzed. The long range molecular coefficients C3 for the 0u+ and 1g states are obtained, and the corresponding empirical potential curves are derived with the spectroscopy data.