Speaker
Description
Relativistic heavy-ion collision events containing rare final states
involving high transverse momentum objects provide in situ probe which
allow characterization of the hot, dense QCD matter formed in these
collisions. When compared with comparable yields in proton-lead and
proton-proton collisions, hadronic jets and quarkonia (both for charm
and bottom quarks) are observed to have significantly modified yields
and fragmentation properties in lead-lead collisions. Details of these
modifications carry information about the interaction of partons with
the medium as well as the properties of the medium. By comparison,
yields of photons and massive electroweak bosons in lead-lead and
proton-lead collisions are found to be essentially unmodified compared
to expectations, including isospin effects. With increasing integrated
luminosities, these measurements can be used to measure nuclear parton
distribution functions and other geometric aspects of the initial state.
This talk will present the most recent results on quarkonia, jet, heavy
flavor and electroweak boson production, measured in Pb+Pb and p+Pb
collisions. The talk covers also includes recent results on gamma-gamma
and photonuclear processes studied in ultraperipheral collisions. This
is a growing program, complementary to inelastic heavy ion collisions,
which produces hard probes via electromagnetically.
