  Enhanced production of events with almost equal-sized fragments is
experimentally revealed by charge correlations in the multifragmentation of a
finite nuclear system selected in $^{129}$Xe central collisions on $^{nat}$Sn.
The evolution of their weight with the incident energy: 32, 39, 45, 50 AMeV, is
measured.Dynamical stochastic mean field simulations performed at 32 AMeV, in
which spinodal instabilities are responsible for multifragmentation, exhibit a
similar enhancement of this kind of events. The above experimental observation
evidences the spinodal decomposition of hot finite nuclear matter as the origin
of multifragmentation in the Fermi energy regime.
