Correlations and fluctuations
- Volker Koch (LBNL)
In this talk, I am going to address three questions about collectivity in heavy ion collisions:
1) What do we mean by collectivity?
2) What distinguish between flow & non-flow?
3) How to interpret the sign of flow cumulants?
The standard picture of heavy ion collisions is that large systems (collisions of large nuclei like Au+Au and Pb+Pb) create a quark-gluon plasma that exhibits collective behavior indicative of nearly inviscid hydrodynamical evolution. Recently, data from small systems (collisions of a small projectile and a large target like d+Au and p+Pb) have been found to exhibit strikingly similar...
In this talk, I will give an overview of recent experimental
measurements of mixed harmonic azimuthal correlations and its rapidity
dependence at RHIC. I will discuss how such measurements over a wide
range of energy can help us explore the longitudinal structure of the
initial state and constrain the temperature dependent transport
properties of the matter formed in relativistic heavy ion collisions.
I will discuss recent experimental and theoretical developments in the subject of two- and multi-particle rapidity correlations in proton-proton, proton-nucleus and nucleus-nucleus collisions. In particular, I will focus on (i) a mysterious baryon-baryon rapidity anti-correlation found at both RHIC and the LHC and (ii) a peculiar scaling in all colliding systems at the LHC of the long-range...