Speaker
Description
Hot QCD medium effects were extensively studied in heavy nucleus-nucleus collisions while the measurements in proton-nucleus (pA) collisions were primarily to study cold nuclear effects. However, the observations of the collective flow of light flavor particles in both proton-proton (pp) and pA collisions raised the question whether the hot medium effects are negligible in small-collision systems. Other explanations for the observed collectivity were also proposed, based on initial momentum correlations. Heavy flavor quarks are almost entirely created via the initial hard processes. They evolve with the whole system, providing unique opportunities to probe both initial-state physics and in-medium effects. We will discuss the measurements for collectivity and productions of heavy flavor particles, including both open heavy flavor hadrons and quarkonia, in pp and proton-lead collisions at the LHC.
