[Submitted on 13 Jun 2025]
Impact of particle production mechanisms on pseudorapidity distribution and directed flow in Au+Au and Cu+Cu collisions at = 19.6 GeV using AMPT model
Muhammad Farhan Taseer🇨🇳 · Subhash Singha🇨🇳
The STAR experiment at the top RHIC energy has observed that the directed flow () of inclusive light hadrons is independent of the collision system size at a given centrality~\cite{STAR:2008jgm}. However, recent STAR measurements indicate a system-size dependence in the -slope () of protons, antiprotons, and their differences () at a given centrality, suggesting a potential influence of baryon production and transport mechanisms~\cite{Taseer:SQM2024talk}. We have studied pseudorapidity () distributions and directed flow ( and ) for pions, kaons, and protons in Au+Au and Cu+Cu collisions at GeV using the A Multi-Phase Transport (AMPT) model. Specifically, we investigated the influence of string junction parameters in AMPT via the PYTHIA/JETSET routines, focusing on the popcorn mechanism and string-splitting parameters, on , , and their charge-dependent splittings ( and ). We observe that string junction parameters can affect , , , and for , K, and p, and influence their system-size dependence. The effect is most prominent on the of protons, non-trivial for kaons, while the pions remain largely unchanged. These findings provide insights into the interplay between particle production mechanisms, baryon transport, and directed flow in heavy-ion collisions.
- Comments:
- 11 pages, 11 figures, accepted in Chin. Phys. C
- Subjects:
- Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
- arXiv:
- 2506.12114 [pdf]