EFFECTS OF PROBABILITY OF REACTION ON ANNIHILATION REACTIONS IN ONE DIMENSION

We report Monte Carlo simulations of annihilation reactions A + A --> 0 in a one-dimensional lattice for hard-core particles. In the model, the particles perform a random walk and can react (occupy the same site and annihilate) with a probability of reaction p less-than-or-equal-to 1. When p << 1, the density of A particles decays at intermediate times approximately as rho(t) approximately t-gamma, after an initial plateau at short times. The exponent gamma is non-universal and depends only on p, 1/2 < gamma < 1. Both the diffusion-controlled and the reaction-controlled reactions limits are recovered when p = 1 and p --> 0, respectively. These results should be relevant for annihilation reactions taking place on effectively low-dimensional substrates of spectral dimension d(s) < 2 such as rough surfaces, porous media and ramified structures.