On the energy loss of high energy quarks in a finite-size quark-gluon plasma

The induced gluon emission from a fast quark passing through a finite-size QCD plasma is studied within the light-cone path integral approach. It is shown that the leading log approximation used in previous studies fails when the gluon formation length becomes on the order of the length of the medium traversed by the quark. Calculation of the energy loss beyond the leading log approximation gives the energy loss which grows logarithmically with quark energy, contrary to the energy-independent prediction of the leading log approximation.