Speaker
Description
Photons and Z boson can be used to constrain the kinematics, as well as the flavor, of the recoiling parton, before its interaction with the quark-gluon plasma. While photons are more abundant, they suffer from larger systematic uncertainties, particularly at low $p_\mathrm{T}$, from the background photons from neutral meson decays. Tagging with Z bosons is a complementary way to study modifications of low $p_\mathrm{T}$ partons as well as the soft particles from the medium response. The talk will present studies of kinematics correlations between Z bosons and charged particles, photon-tagged jet fragmentation functions and the jet shapes in pp and PbPb collisions at $\sqrt{s_\mathrm{NN}} = 5.02\,\mathrm{TeV}$ using data collected with the CMS detector.
