TY  - JOUR
A1  - Greif, Moritz
A1  - Greiner, Carsten
A1  - Schenke, Björn Peter
A1  - Schlichting, Sören
A1  - Xu, Zhe
T1  - Importance of initial and final state effects for azimuthal correlations in p+Pb collisions
T2  - Nuclear Physics A
N2  - We study the influence and interplay of initial state and final state effects in the dynamics of small systems, focusing on azimuthal correlations at different multiplicities. To this end we introduce a new model, 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. Depending on multiplicity of the event, we see transverse momentum dependent signatures of the initial, but also the final state in azimuthal correlation observables, such as v2 {2PC}(pT). In low-multiplicity events, initial state correlations dominate for transverse momenta pT > 2 GeV, whereas in high-multiplicity events and at low momenta final state interactions dominate and initial state correlations strongly affect v2 {2PC}(pT) for pT > 2 GeV as well as the pT integrated v2 {2PC}. Nearly half of the final pT integrated v2 {2PC} is contributed by the initial state in low-multiplicity events, whereas in high-multiplicity the share is much less. Based on Ref. [M. Greif, C. Greiner, B. Schenke, S. Schlichting, Z. Xu, Phys. Rev. D96 (9) (2017) 091504], we are now able to carry out a systematic multiplicity scan, probing the dynamics on the border of initial state dominated to final state dominated – but not yet hydrodynamic regime.
KW  - Parton cascade BAMPS
KW  - IPGLASMA
KW  - Initial state
KW  - Final state
KW  - Small systems
Y1  - 2019
UR  - http://publikationen.ub.uni-frankfurt.de/frontdoor/index/index/docId/77615
UR  - https://nbn-resolving.org/urn:nbn:de:hebis:30:3-776150
SN  - 0375-9474
VL  - 982
SP  - 491
EP  - 494
PB  - Elsevier
CY  - Amsterdam
ER  -