https://doi.org/10.1140/epjc/s10052-024-13276-6
Regular Article - Theoretical Physics
Quasi particle model vs lattice QCD thermodynamics: extension to 
flavors and momentum dependent quark masses
1
Department of Physics and Astronomy, University of Catania, Via S. Sofia 64, 95123, Catania, Italy
2
Laboratori Nazionali del Sud, INFN-LNS, Via S. Sofia 62, 95123, Catania, Italy
Received:
3
May
2024
Accepted:
20
August
2024
Published online:
2
September
2024
In the last decade a quasi-particle model (QPM) has supplied the basis for the study of heavy quark (HQ) production in ultra-relativistic collisions, allowing for a phenomenological estimate of the HQ diffusion coefficient 
. Using the new lattice QCD results for the equation of state (EoS) with 2+1+1 dynamical flavors, we extend the QPM from 
to , where the charm quark is included. Fixing the coupling g(T) by a fit to the lQCD energy density 
, we evaluate the impact of different temperature parametrizations of charm quark mass on EoS and susceptibilities 
of light, 
of strange and 
of charm quarks, the last favouring a charm quark mass increasing toward 
. We also explore the extension of the QPM to a more realistic approach called QPM
, where quark and gluon masses explicitly depend on their momentum converging to the current quark mass at high momenta, as expected from asymptotic free dynamics. The QPM allows for a simultaneous quantitative description not only of the EoS but also of the quark susceptibilities (, ), which instead are underestimated in the simple QPM. Furthermore, evaluating the spatial diffusion coefficient 
in the QPM, we find it is also closer than QPM to the recent lQCD data performed including dynamical fermions. Finally, in a 1+1D expanding system, we evaluate the 
in the QPM and QPM, finding a significant reduction at low momenta for QPM which could lead in a realistic scenario to a better agreement to experimental data.
© The Author(s) 2024
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Funded by SCOAP3.
