  We investigate the dynamics of a 1D Bose gas after a quench from the
Tonks-Girardeau regime to the regime of strong attractive interactions applying
analytical techniques and exact numerical simulations. After the quench the
system is found to be predominantly in an excited gas-like state, the so-called
super-Tonks gas, however with a small coherent admixture of two-particle bound
states. Despite its small amplitude, the latter component leads to a rather
pronounced oscillation of the local density-density correlation with a
frequency corresponding to the binding energy of the pair, making two-particle
bound states observable in an experiment. Contributions from bound states with
larger particle numbers are found to be negligible.
