17–31 Jul 2025
Orthodox Academy of Crete, Kolymbari, Crete, Greece
Europe/Athens timezone
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Exploring system size dependence of directed flow in heavy-ion collisions through the transport model

21 Jul 2025, 19:00
20m
Room 1

Room 1

Talk Heavy Ion Collisions and Critical Phenomena Heavy Ion Collisions and Critical Phenomena

Speaker

Dr Kishora Nayak (Panchayat College (Govt.), Sambalpur University)

Description

Directed flow ($v_1$) is the first-order harmonic of the Fourier expansion of the particle azimuthal angle distribution with respect to the reaction plane. It describes the collective sideward deflection of particles and is believed to be generated in the very early stages of heavy-ion collisions. Various hydrodynamic and nuclear transport models suggest that $v_{1}$ in the mid-rapidity region is sensitive to the expanding participant matter during the initial collision stages. The bulk of Quark-Gluon Plasma (QGP) is primarily composed of low-$p_{T}$ hadrons produced through soft processes, exhibiting a tilt in rapidity. The asymmetry between hadrons produced from hard and soft processes in the initial state results in a negative $v_{1}$ for hard partons. Therefore, $p_{T}$ dependence of $v_{1}$ is crucial for understanding the hard-soft asymmetry in the flow profile of heavy-ion collisions. Additionally, system size dependence of $v_{1}$ enhances our understanding of the collective dynamics and the subsequent evolution of QCD matter, providing valuable insights into the initial conditions of heavy-ion collisions.

In this talk, we will present rapidity-odd directed flow in various collision systems (O+O, Cu+Cu, Ru+Ru, Zr+Zr, Au+Au, and U+U) at $\sqrt{s_{NN}} =$ 200 GeV using using a multi-phase transport model (AMPT) model. We will discuss the dependence of $v_{1}$ on pseudo-rapidity ($\eta$) and transverse momentum ($p_{T}$). We will also discuss the slope of directed flow ($dv_{1}/dy$) across different systems and compared with the available experimental results.

Details

Dr. Kishora Nayak, Panchayat College (Govt.), Sambalpur University
(https://panchayatcollege.in/)

Internet talk Yes
Is this an abstract from experimental collaboration? No
Name of experiment and experimental site N/A
Is the speaker for that presentation defined? Yes

Author

Dr Vipul Bairathi (Instituto de Alta Investigación, Universidad de Tarapacá)

Co-author

Dr Kishora Nayak (Panchayat College (Govt.), Sambalpur University)

Presentation materials