Institut de recherche sur les lois fondamentales de l'Univers

Direction de la recherche fondamentale

Résumé du preprint DAPNIA-04-120

DAPNIA-04-120
Model-independent tracking of criticality signals in nuclear multifragmentation data
J.D.Frankland, A.Chbihi, A.Mignon, M.L.Begemann-Bleich, R.Bittiger, B.Borderie, R.Bougault, J.L.Charvet, D.Cussol, R.Dayras, D.Durand, C.Escano-Rodriguez, E.Galichet, D.Guinet, P.Lautesse, A.LeFevre, R.Legrain, N.LeNeindre, O.Lopez, J.Lukasik, U.Lynen, L.Manduci, J.Marie, W.F.J.Mueller, H.Orth, M.Parlog, M.Pichon, M.F.Rivet, E.Rosato, R.Roy, A.Saija, C.Schwarz, C.Sfienti, B.Tamain, W.Trautmann, A.Trczinski, K.Turzo, A.VanLauwe, M.Vigilante, C.Volant, J.P.Wieleczko, and B.Zwieglinski
We look for signals of criticality in multifragment production in heavy-ion collisions using model-independent universal fluctuations theory. The phenomenon is studied as a function of system size, bombarding energy, and impact parameter in a wide range of INDRA data. For very central collisions (b/bmax < 0.1) we find evidence that the largest fragment in each event, Zmax, plays the role of an ordre parameter, defining two different \"phases\" at low and high incident energies, respectively, according to the scaling properties of its fluctuations. Data for a wide range of system masses and incident energies collapse on to an approximately universal scaling function in each phase for the most central collisions. The forms of the scaling functions for the two phases are established, and their dependence on the total mass and the bombarding energy is mapped out. Data suggest that these phases are linked to the disappearance of heavy residues in central collisions.

DAPNIA-04-120

Model-independent tracking of criticality signals in nuclear multifragmentation data

J.D.Frankland, A.Chbihi, A.Mignon, M.L.Begemann-Bleich, R.Bittiger, B.Borderie, R.Bougault, J.L.Charvet, D.Cussol, R.Dayras, D.Durand, C.Escano-Rodriguez, E.Galichet, D.Guinet, P.Lautesse, A.LeFevre, R.Legrain, N.LeNeindre, O.Lopez, J.Lukasik, U.Lynen, L.Manduci, J.Marie, W.F.J.Mueller, H.Orth, M.Parlog, M.Pichon, M.F.Rivet, E.Rosato, R.Roy, A.Saija, C.Schwarz, C.Sfienti, B.Tamain, W.Trautmann, A.Trczinski, K.Turzo, A.VanLauwe, M.Vigilante, C.Volant, J.P.Wieleczko, and B.Zwieglinski

We look for signals of criticality in multifragment production in heavy-ion collisions using model-independent universal fluctuations theory. The phenomenon is studied as a function of system size, bombarding energy, and impact parameter in a wide range of INDRA data. For very central collisions (b/bmax < 0.1) we find evidence that the largest fragment in each event, Zmax, plays the role of an ordre parameter, defining two different \"phases\" at low and high incident energies, respectively, according to the scaling properties of its fluctuations. Data for a wide range of system masses and incident energies collapse on to an approximately universal scaling function in each phase for the most central collisions. The forms of the scaling functions for the two phases are established, and their dependence on the total mass and the bombarding energy is mapped out. Data suggest that these phases are linked to the disappearance of heavy residues in central collisions.