Half-life and heavy tail in the disruption of three-body systems

We measure the lifetime distribution of non-hierarchical three-body systems in 9,000 regularized planar integrations, with equal masses, with two light masses and one heavy mass, and with two heavy masses and one light mass, starting from rest and with virial ratio 0.5, up to ten thousand crossing times. The half-life, the median lifetime, ranges from about 3 to 30 crossing times and decreases with the mass disparity. The disruption, however, is not exponential: from 0.8% to 8% of the systems survive to one thousand crossing times, many orders of magnitude above the exponential prediction, and the survival tail approximately follows a power law. In the start from rest, the exponent lies between 0.63 and 0.94, close to the value 2/3 predicted for Lévy flights, and the long-lived systems are dominated by a single long excursion. In the virial start, the tail is heavier, with an exponent between 0.17 and 0.45, and, with a heavy pair, the long-lived systems are nearly stable hierarchical configurations, with hundreds of revolutions of the light body.