2019 Impact factor 2.176
Hadrons and Nuclei


Eur. Phys. J. A 11, 421-426 (2001)

Lyapunov exponent, generalized entropies and fractal dimensions of hot drops

C.O. Dorso1, 2 and A. Bonasera1

1  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.

PACS
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