Success and challenges of flow harmonic analysis in LHC collisions from large to small systems

Abstract

One of the primary goals of heavy-ion physics is to understand the transport properties of the quark-gluon-plasma (QGP) which comprises the tiniest constituents, quarks and gluons, that prevailed in the first few microseconds after the Big Bang. The present most challenging part of the research is pinning down the critical point of the QGP, where the shear viscosity over entropy ratio (η/s) is at its minimum and very close to the lowest value in nature 1/(4π). Significant advances based on flow harmonic analysis have been made up to date. However, there are still few remaining challenges in experiments and theory to constrain the temperature dependence of η/s and ζ/s of the QGP. In this talk, I will highlight the latest results from LHC experiments in this regard and discuss aforementioned challenges.