QCD Collisional Energy Loss Reexamined

It is shown that at a large temperature and E→∞ the QCD collisional energy loss reads dE/dx~α(mD²)T². Compared to previous approaches, which led to dEB/dx~α²T²ln(ET/mD²) similar to the Bethe-Bloch formula in QED, we take into account the running of the strong coupling. As one significant consequence, due to asymptotic freedom, $dE/dx$ becomes E independent for large parton energies. Some implications with regard to heavy ion collisions are pointed out.