title: Annealed and quenched disorder in sand-pile models with local violation of conservation.
abstract: In this paper we consider the Bak, Tang, and Wiesenfeld (BTW) sand-pile model with local violation of conservation through annealed and quenched disorder. We have observed that the probability distribution functions of avalanches have two distinct exponents, one of which is associated with the usual BTW model and another one which we propose to belong to a new fixed point; that is, a crossover from the original BTW fixed point to a new fixed point is observed. Through field theoretic calculations, we show that such a perturbation is relevant and takes the system to a new fixed point.
authors.affiliation: Physics Department, Sharif University of Technology, Post Office Box 11155-9161, Tehran, Iran.
authors.forename: Saman
authors.initials: S
authors.lastname: Moghimi-Araghi
authors.affiliation: Physics Department, Sharif University of Technology, Post Office Box 11155-9161, Tehran, Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Sebtosheikh