Intermittency in 197Au fragmentation
Abstract
The concept of factorial moments was applied to an analysis of the dynamical fluctuations in the charge distributions of the fragments emitted from gold nuclei with energies 10.6 and <1.0 GeV/nucleon interacting with emulsion nuclei. Clear evidence for intermittent fluctuations has been found in an analysis using all the particles released from the gold projectile, with a stronger effect observed below 1 GeV/nucleon than at 10.6 GeV/nucleon. For the full data sets, however, the intermittency effect was found to be very sensitive to the singly charged particles, and neglecting these particles strongly reduces the intermittency signal. When the analysis is restricted to the multiply charged fragments, an intermittency effect is revealed only for multifragmentation events, although one that is enhanced as compared to the analysis of all, singly and multiply charged, particles. The properties of the anomalous fractal dimensions suggest a sequential decay mechanism, rather than the existence of possible critical behavior in the process of nuclear fragmentation. The likely influence of the charge conservation effects and the finite size of decaying systems on the observed intermittency signals was pointed out.