%0 Journal Article %T A system of grabbing particles related to Galton-Watson trees %A Jean Bertoin %A Vladas Sidoravicius %A Maria Eulalia Vares %J Mathematics %D 2008 %I arXiv %X We consider a system of particles with arms that are activated randomly to grab other particles as a toy model for polymerization. We assume that the following two rules are fulfilled: Once a particle has been grabbed then it cannot be grabbed again, and an arm cannot grab a particle that belongs to its own cluster. We are interested in the shape of a typical polymer in the situation when the initial number of monomers is large and the numbers of arms of monomers are given by i.i.d. random variables. Our main result is a limit theorem for the empirical distribution of polymers, where limit is expressed in terms of a Galton-Watson tree. %U http://arxiv.org/abs/0804.0726v2