Angular structure of energy losses of hard jet in dense QCD-matter

Angular structure of radiative and collisional energy losses of a hard parton jet propagating through dense QCD-matter is investigated. For small angular jet cone sizes, $\theta_0 < 5^0-10^0$, the radiative energy loss is shown to dominate over the collisional energy loss due to final state elastic rescattering of the hard projectile on thermal particles in the medium. Due to coherent effects, the radiative energy loss decreases with increasing the angular size the jet. It becomes comparable with the collisional energy loss for $\theta_0 > 10^0$.