PROBING THE QUARK-GLUON PLASMA AT THE LHC WITH Z⁰-TAGGED JETS IN CMS

An important tool in quark-gluon plasma studies at RHIC has been the measurement of dijets investigated via leading hadron correlations. With much higher rates for hard processes at the Large Hadron Collider, studies of Z 0 -tagged jets become possible. A clear experimental signature is provided by the measurement of muon pairs from the Z 0 decays, for which CMS is an ideally suited detector. Instead of measuring back-to-back correlations of two strongly interacting particles, one side is replaced by an electromagnetic probe which propagates through the plasma undisturbed and provides a measurement of the energy of the initial hard scattering. We propose to use lepton-pair tagged jets to study medium-induced partonic energy loss and to measure in-medium parton fragmentation functions. The lepton pairs from semileptonic decays of heavy meson pairs ([Formula: see text] and [Formula: see text]) are a background source for the tagged dilepton-jet signal. We present the calculated signal rates (using PYTHIA) and background rates (using HVQMNR). We also discuss strategies for maximizing the signal-to-background ratio.