  Hard probes created through large momentum transfers are used to study the
properties of QCD matter created in heavy-ion collisions, by comparing the
measurements to those in p+p collisions. Jets, and the "quenching" or
suppression of jets in the medium created in heavy-ion collisions, are studied
through various different observables. We present the most recent measurements
from $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions, with p+p collisions as the
reference, by the STAR Collaboration. The observables are semi-inclusive
charged jets and di-jet transverse momentum imbalance. Additionally,
correlation measurements of direct photon-hadron and neutral pion-hadron are
presented and discussed.
