Heavy-quark contributions to the ratio F_L/F_2 at low x

Alexey Yu. Illarionov, Bernd A. Kniehl, Anatoly V. Kotikov

We study the heavy-quark contribution to the proton structure functions F_2^i(x,Q^2) and F_L^i(x,Q^2), with i=c,b, for small values of Bjorken's x variable at next-to-lading order…