Through a mixed level, which has characters of both the A(1)Sigma(u)(+) and b(3)Pi(u) states of Li-2, several singlet and triplet Rydberg states are accessed simultaneously using an ultrafast laser. The electronic, vibrational and rotational wave packets of these Rydberg states are detected. Since a single member of the excited superposition, 2(3)Sigma(g)(+) (v = 12, N = 16), is predissociative, the intensities of the quan turn beats that have a component of this state decrease much faster with time (approximate to250 ps) than the other stable states. The polarization dependence of the quantum beats is utilized to assign the spectra. (C) 2004 Elsevier B.V. All rights reserved.