The limit distributions of the macroscopic variable which is the sum of a large number N of uncorrelated random microscopic variables have been completely solved when N--->Infinity [1]. On the contrary, little is known about limiting features for the sum of correlated variables.
This major problem in Physics, is a primary obstacle in understanding finite systems such as e.g. formed in the energetic collisions of atomic nuclei. Recently, it has been shown rigorously that these distributions for finite N, both for correlated and uncorrelated random variables, approach the asymptotic limit in a universal way, called the delta-scaling law [2]. This opened the possibility to study different phases and transitions in hot hadronic matter in a rigorous, model -and assumption- independent way. Particularly encouraging are studies of the phases of nuclear matter at low and intermediate excitation energies where relevant observables for generic scenarios of fragment production can be measured.
High precision INDRA multidetector system allowed for the first time to measure universal fluctuations of observables associated with the delta-scaling law in nuclear matter [3]. These studies are now actively pursued both experimentally and theoretically. Contact: M. Ploszajczak |
References: [1] P. Lévy, Compositio Mathematica 7 (1940) 283.
[2] R. Botet and M. Ploszajczak, Phys. Rev. E 57, 7305; ibid. E 62, 1825.
[3] R. Botet, M. Ploszajczak, A. Chbihi, B. Borderie, D. Durand and J. Frankland, Phys. Rev. Lett. 86, 3514. |
