Speaker
Description
Authors: S. Glässel, V. Kireyeu, G. Coci, V. Voronyuk, M. Winn, J. Aichelin, C. Blume, and E. Bratkovskaya
We investigate the influence of the equation-of-state (EoS) of strongly interacting hadronic and partonic matter created in heavy-ion collisions on the light cluster and hypernuclei production within the Parton-Hadron-Quantum-Molecular Dynamics (PHQMD) microscopic transport approach (PHQMD) [1-5]. The PHQMD is a microscopic n-body transport model based on the QMD propagation of the baryonic degrees of freedom, where the clusters are formed dynamically, via {\bf 'potential' mechanism}, i.e. by potential interactions between nucleons and hyperons, and recognized by by the Minimum Spanning Tree (MST) algorithm which is identifying bound clusters by correlations of baryons in coordinate space.
Additionally, {\bf 'kinetic' mechanisms for deuteron production} is incorporated by catalytic hadronic reactions accounting all isospin channels of the various $\pi NN\leftrightarrow \pi d$, $NNN\leftrightarrow N d$ reactions which enhances deuteron production as well as considering the quantum nature of the deuteron by mean of its finite size modelled by the finite-size excluded volume effect in coordinate space and projection of relative momentum of the interacting pair of nucleons on the deuteron wave-function in momentum space, leads to a strong reduction of d production, especially at target/projectile rapidities [4].
Whereas in the previous PHQMD calculations we employed a static interaction between nucleons, now we include a {\bf momentum dependence interaction}. The parameters of the momentum dependent potential are fitted to the 'optical' potential, extracted from elastic pA scattering data. The potential is increasingly repulsive up to $E_{kin}\sim 1.5$ GeV, therefore its influence depends on the beam energy. A momentum dependent interaction acts very differently on flow observables like $v_1$ or $v_2$ and cluster rapdity distributions and brings the calculations even closer to the experimental data as a comparison with STAR data shows.
We have furthermore implemented {\bf the coalescence approach in the PHQMD } what allows to compare directly and for the same underlying dynamics the cluster yields, created by MST+kinetic mechanisms and coalescence mechanism. We could establish that both methods yield different cluster rapidity distributions. This allows to {\bf determine the cluster production mechanism experimentally}. Finally we will present a solution of the 'ice in the fire' puzzle, the question how cluster can survive the expansion of the hot and strongly interacting fireball at midrapidity.
[1] J. Aichelin, E. Bratkovskaya, A. Le Fevre, V. Kireyeu, V. Kolesnikov, Y. Leifels, V. Voronyuk and G. Coci, Phys. Rev. C101 (2020) 044905, [arXiv:1907.03860 [nucl-th]].
[2] S. Glässel, V. Kireyeu, V. Voronyuk, J. Aichelin, C. Blume, E. Bratkovskaya, G. Coci, V. Kolesnikov and M. Winn, Phys. Rev. C105 (2022) 014908, [arXiv:2106.14839 [nucl-th]].
[3] V. Kireyeu, J. Steinheimer, J. Aichelin, M. Bleicher and E. Bratkovskaya, Phys. Rev. C105 (2022) 044909, [arXiv:2201.13374 [nucl-th]].
[4] G. Coci, S. Glässel, V. Kireyeu, J. Aichelin, C. Blume, E. Bratkovskaya, V. Kolesnikov and V. Voronyuk, Phys. Rev. C108 (2023) 014902, [arXiv:2303.02279 [nucl-th]].
[5] V. Kireyeu, G. Coci, S. Glaessel, J. Aichelin, C. Blume and E. Bratkovskaya, [arXiv:2304.12019 [nucl-th]].
| session | G. Heavy Ion Physics |
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