Eur. Phys. J. A 11, 421-426 (2001)
Lyapunov exponent, generalized entropies and fractal dimensions of hot drops
C.O. Dorso1, 2 and A. Bonasera11 Laboratorio Nazionale del Sud, Istituto Nazionale di Fisica Nucleare, via S. Sofia 44, I-95123 Catania, Italy
2 Departamento de Fisica, Facultad de Ciencias Exactas y Naturales Universidad de Buenos Aires Pabellon I, Ciudad Universitaria, Nuñez 1428 Buenos Aires, Argentina
bonasera@lns.infn.it
(Received: 16 March 2001 / Revised version: 15 May 2001 Communicated by P. Schuck)
Abstract
We calculate the maximal Lyapunov exponent, the generalized entropies, the
asymptotic distance between nearby trajectories and the fractal dimensions
for a finite two-dimensional system at different initial excitation
energies. We show that these quantities have a maximum at about the same
excitation energy. The presence of this maximum indicates the transition
from a chaotic regime to a more regular one. In the chaotic regime the
system is composed mainly of a liquid drop while the regular one corresponds
to almost freely flowing particles and small clusters. At the transitional
excitation energy the fractal dimensions are similar to those estimated from
the Fisher model for a liquid-gas phase transition at the critical point.
25.70.Mn - Projectile and target fragmentation.
05.45.-a - Nonlinear dynamics and nonlinear dynamical systems.
05.70.Jk - Critical point phenomena.
© Società Italiana di Fisica, Springer-Verlag 2001
