Equilibration of N/Z in binary breakup of an excited and transiently deformed projectile-like fragment (PLF*), produced in peripheral collisions of 64Zn + 27Al, 64Zn, 209Bi at E/A = 45 MeV, is examined. The composition of emitted light fragments (3<=Z<=6) changes with the decay angle of the PLF*. The most neutron-rich fragments observed are associated with a small rotation angle. A clear target dependence is observed with the largest initial N/Z correlated with the heavy, neutron-rich target. Using the rotation angle as a clock, we deduce that N/Z equilibration persists for times as long as 3-4 zs (1zs = 1 x 10^-21 s = 300 fm/c). The rate of N/Z equilibration is found to depend on the initial neutron gradient within the PLF*.
@article{arxiv.1305.1320,
title = {Timescale for equilibration of N/Z gradients in dinuclear systems},
author = {K. Brown and S. Hudan and R. T. de Souza and J. Gauthier and R. Roy and D. V. Shetty and G. A. Souliotis and S. J. Yennello},
journal= {arXiv preprint arXiv:1305.1320},
year = {2015}
}