%D 1998 %A Alessandro Chessa %A Enzo Marinari %A Alessandro Vespignani %A Stefano Zapperi %X We present results of large scale numerical simulations of the Bak, Tang, and Wiesenfeld [Phys. Rev. Lett. 59, 381 (1987); Phys. Rev. A 38, 364 (1988)] sandpile model. We analyze the critical behavior of the model in Euclidean dimensions 2<~d<~6. We consider a dissipative generalization of the model and study the avalanche size and duration distributions for different values of the lattice size and dissipation. We find that the scaling exponents in d=4 significantly differ from mean-field predictions, thus suggesting an upper critical dimension dc>~5. Using the relations among the dissipation rate ? and the finite lattice size L, we find that a subset of the exponents displays mean-field values below the upper critical dimensions. This behavior is explained in terms of conservation laws. %L eprints1871 %I American Physical Society %K PACS: 64.60.Lx, 05.40.+j, 05.70.Ln %V 57 %P R6241-R6244 %J Physical Review E %R 10.1103/PhysRevE.57.R6241 %T Mean-field behavior of the sandpile model below the upper critical dimension