Two- and Three-Particle Jet Correlations from STAR

Hard-soft charged hadron angular correlations are shown. Away-side associated 〈pT〉 is studied. Angular correlations with trigger baryon and meson are compared. Three-particle correlations are presented for the first time.Relativistic heavy-ion collisions may create the quark-gluon plasma (QGP), a state of deconfined and thermalized quarks and gluons predicted by quantum chromodynamics (QCD) at high energy densities [F. Karsch, Nucl Phys A698, 199c (2002)]. To study the medium created in heavy-ion collisions we use jets. Jets are used because they can be calculated by perturbative QCD and thus are well calibrated in the vacuum and because they can be modified by the medium and thus provide information about the medium [X.-N. Wang and M. Gyulassy, Phys. Rev. Lett. 68, 1480 (1992); R. Baier, D. Schiff, and B.G. Zakharov, Ann. Rev. Nucl. Part. Sci. 50, 37 (2000)].