May 13 – 19, 2018
Venice, Italy
Europe/Zurich timezone
The organisers warmly thank all participants for such a lively QM2018! See you in China in 2019!

Factorization of two-particle probability distributions in Pb--Pb collisions at $\sqrt{s_{NN}} = 5.02$ TeV with ALICE

May 15, 2018, 5:00 PM
2h 40m
First floor and third floor (Palazzo del Casinò)

First floor and third floor

Palazzo del Casinò

Poster Collective dynamics Poster Session


Christian Bourjau (University of Copenhagen (DK))


The flow coefficients $v_n$ are commonly extracted from multi-particle distributions where the properties of one or several particles are averaged over a large range in pseudorapidity $\eta$ or transverse momentum $p_{\text{T}}$.
Such approaches assume that the observed multi-particle distributions can be factorized into a product of single-particle distributions.
However, it is known that this condition is violated even in ideal hydrodynamics due to initial state fluctuations or the presence of non-flow.
Detailed studies of a possible violation of this factorization assumption can therefore be used to constrain the size of such fluctuations as well as to identify possible non-flow contributions.
A factorization breakdown can be measured directly in multi-particle probability distributions.
This poster presents an explicit approach to the $\eta$-dependent factorization of two-particle probability distributions within $-3.4 \leq \eta \leq 5$ in the latest $\sqrt{s_{NN}} = 5.02$ TeV Pb--Pb data measured with ALICE.
A factorizing phase-space region is identified by varying the minimal $\Delta\eta$ separation between particles; the factorization breakdown for small separations is attributed to non-flow and detector effects.
The analysis yields the well known $v_n$ coefficients as the result of the factorization process.
These flow coefficients are compared to similar results measured with the Q-cumulant method.
All findings are also compared to model calculations and previous studies at $\sqrt{s_{NN}} = 2.76$ TeV.

Collaboration ALICE
Content type Experiment
Centralised submission by Collaboration Presenter name already specified

Primary author

Christian Bourjau (University of Copenhagen (DK))

Presentation materials