Critical behavior of the one-dimensional annihilation-fission process 2A-->O, 2A-->3A

Numerical simulations and cluster mean-field approximations with coherent anomaly extrapolation show that the critical line of the 1d annihilation-fission process is separated into two regions. In both the small and high diffusion cases, the critical behavior is different from the well known universality classes of nonequilibrium phase transitions to absorbing states. The high diffusion region seems to be well described by the cyclically coupled directed percolation and annihilating random walk. Spreading exponents show nonuniversal behavior.