Particle Survival and Polydispersity in Aggregation

Abstract

We study the probability, $P_S(t)$, of a cluster to remain intact in one-dimensional cluster-cluster aggregation when the cluster diffusion coefficient scales with size as $D(s) \sim s^γ$. $P_S(t)$ exhibits a stretched exponential decay for $γ< 0$ and the power-laws $t^{-3/2}$ for $γ=0$, and $t^{-2/(2-γ)}$ for $0<γ<2$. A random walk picture explains the discontinuous and non-monotonic behavior of the exponent. The decay of $P_S(t)$ determines the polydispersity exponent, $τ$, which describes the size distribution for small clusters. Surprisingly, $τ(γ)$ is a constant $τ= 0$ for $0<γ<2$.