Structure of Giant Nuclear Molecules

Strong indirect evidence exists for the existence of attractive forces between nuclei making surface contact. Experimentally, the recent observations of spontaneous positron production in heavy-ion collisions can only be understood if nuclei stick together for times long compared to the collision time. We show that any such tendency for nuclei to attract implies the existence of nuclear molecules with entirely new kinds of collective modes. We present a simple model for these modes and apply it to ${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$-${}_{}{}^{238}{}_{}{}^{}\mathrm{U}$.