Intermittency studies in directed bond percolation

The self-similar cluster fluctuations of directed bond percolation at the percolation threshold are studied using techniques borrowed from intermittency-related analysis in multi-particle production. Numerical simulations based on the factorial moments for large 1 + 1-dimensional lattices allow to handle statistical and boundary effects and show the existence of weak but definite intermittency patterns. The extracted fractal dimensions are in agreement with scaling arguments leading to a new relation linking the intermittency indices to the critical exponents and the fractal dimension of directed percolation clusters. Supported in part by the Swiss National Science Foundation 2 Laboratoire de la Direction des Sciences de la Matière du Commissariat à l’Energie