QCD factorization with heavy quarks
  We further analyze the definition and the calculation of the heavy quark impact factor at next-to-leading (NL) $\log s$ level, and we provide its analytical expression in a previously proposed k-factorization scheme. Our results indicate that k-factorization holds at NL level with a properly chosen energy scale, and with the same gluonic Green's function previously found in the massless probe case. 
German Rodrigo (Karlsruhe U.) and Marcello Ciafaloni (Florence U. &   INFN, Florence)