Täuber, Uwe C.Howard, M. J.Hinrichsen, H.2016-09-302016-09-301998-03-090031-9007http://hdl.handle.net/10919/73086We study a hierarchy of directed percolation (DP) processes for particle species A, B, . . ., unidirectionally coupled via the reactions A → B, . . .. When the DP critical points at all levels coincide, multicritical behavior emerges, with density exponents β^(k) which are markedly reduced at each hierarchy level k ≥ 2. We compute the fluctuation corrections to β⁽²⁾ to O(ϵ = 4 − d) using field-theoretic renormalization group techniques. Monte Carlo simulations are employed to determine the new exponents in dimensions d ≤ 3.2165 - 2168 page(s)In CopyrightArticle - Refereedhttps://doi.org/10.1103/PhysRevLett.80.21658010