Hard scattering phenomena from RHIC to LHC.

In the Relativistic Heavy Ion Collider era the high-p_T particle emerging from hard scattering became an important tool of exploration of excited nuclear medium formed in ultra-relativistic heavy ion collisions. Discovery of anomalous suppression of high-p_T particle yield [1] together with an observation of disappearance of back-to-back hadron correlation in central Au+Au collisions in 2002 [2] were the key results interpreted as a manifestation of the deconfined QCD medium in heavy ion collisions. Analysis of the high-p_T particle and jet production is already a standard experimental technique providing a test bench for pQCD description of the point-like constituent scattering in p+p collisions and sensitive probes of the excited nuclear medium in A+A collisions. [ABSTRACT FROM AUTHOR]