Wavepacket dynamics on the ground and on the optically dark, first electronic state of all-trans-beta-carotene is presented. Ground state dynamics are studied using resonant and non-resonant degenerate four-wave mixing spectroscopy with 16 fs time resolution, Wavepacket motion on the electronic dark state was monitored using pump-degenerate four-wave mixing spectroscopy. (C) 2004 Elsevier B.V. All rights reserved.