High pT particles @ RHIC. Motivation

• Products of parton fragmentation (jet “leading particle”).

• Early production in parton-parton scatterings with large Q2.

• Direct probes of partonic phases of the reaction  Sensitive to dense medium properties: QGP energy loss, saturated CGC ...

• Info on medium effects accessible through comparison to nuclear- geometry scaled "vacuum" (pp) yields:

• or

• Production yields calculable theoretically (next slide) ...

Notes: