Surface critical behavior of random systems: Ordinary transition - art. no. 056102

We calculate the surface critical exponents of the ordinary transition occu rring in semi-infinite, quenched dilute Ising-like systems. This is done by applying the field theoretic approach directly in d = 3 dimensions up to t he two-loop approximation as well as in 4 - epsilon dimensions. At d = 4 - epsilon we extend, up to the next-to-leading order, the previous first-orde r results of the root epsilon expansion by Ohno and Okabe [Phys. Rev. B 46, 5917 (1992)]. In both cases numerical estimates for surface exponents are computed using Pade approximants extrapolating the perturbation theory expa nsions. The obtained results indicate that the critical behavior of semi-in finite systems with quenched bulk disorder is characterized by the new set of surface critical exponents.