May 13 – 19, 2018
Venice, Italy
Europe/Zurich timezone
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Importance of initial and final state effects for azimuthal correlations in p+Pb collisions

May 15, 2018, 3:00 PM
Sala Mosaici-1, 3rd Floor (Palazzo del Casinò)

Sala Mosaici-1, 3rd Floor

Palazzo del Casinò

Parallel Talk Collectivity in small systems Collectivity in small systems


Moritz Greif (University of Frankfurt)


We investigate the relative importance of initial and final state effects on azimuthal correlations in low and high multiplicity p+Pb collisions at LHC energies. By matching the classical Yang-Mills dynamics of pre-equilibrium gluon fields (IP-GLASMA) to a perturbative QCD based parton cascade for the final state evolution (BAMPS) on an event-by-event basis, we find that signatures of both the initial state correlations and final state interactions are seen in azimuthal correlation observables, such as $v_2\{2P C\}(p_T)$, with their relative strength depending on the event multiplicity and transverse momentum. Initial state correlations dominate elliptic flow in low multiplicity events for transverse momenta $p_T > 2~\mathrm{GeV}$. While final state interactions are dominant in high multiplicity events and at low momenta, we find that initial state correlations strongly affect $v_2\{2P C\}(p_T)$ for $p_T>2$ GeV as well as the pT integrated $v_2\{2P C\}$. By carrying out a systematic multiplicity scan, we can also probe the dynamics on the border of initial state dominated to final state dominated - but not yet fully developed hydrodynamic – regime. We predict at which multiplicity and transverse momentum many-body QCD effects in the initial state can be experimentally unveiled.

Reference: Greif, Greiner, Schenke, Schlichting, Xu: Phys. Rev. D 96, 091504, 2017

Content type Theory
Centralised submission by Collaboration Presenter name already specified

Primary authors

Moritz Greif (University of Frankfurt) Soeren Schlichting (University of Washington) Bjoern Schenke (Brookhaven National Lab) Carsten Greiner (University of Frankfurt) Zhe Xu

Presentation materials