Speaker
Description
In the past years, a Quasi-Particle Model (QPM) has been developed to study charm quark dynamics in ultra-relativistic heavy-ion collisions supplying a satisfactory description of both the $R_{AA}(p_T)$ and $v_2(p_T)$ of D mesons and leading to a first evaluation of the spatial diffusion coefficient $D_s(T)$ from the phenomenology [1,2]. Within an event-by-event full Boltzmann transport approach followed by a hybrid hadronization via coalescence plus fragmentation, we will discuss for the first time $R_{AA}(p_T), v_2(p_T)$ and $v_3(p_T)$ predictions down to $p_T \rightarrow 0$ for D and B mesons as well as $\Lambda_c$ and $\Lambda_b$ at both RHIC-sPHENIX and LHC energies [3]. Furthermore the analysis is extended to higher order anisotropic flows $v_n$ of D mesons, also evaluated by using the Event-Shape-Engineering (ESE) technique [4]. We find that QPM approach is able to correctly predict not only the new observables related to charm quark sector, but also the first available data on $R_{AA}(p_T)$ and $v_2(p_T)$ of single-electron from B mesons decays measured by ALICE. The role of the large $\Lambda_c$ and $\Lambda_b$ production is relevant especially in the low $p_T$ region that is becoming accessible to sPHENIX and ALICE.
A significant breaking of the expected scaling of the thermalization time $\tau_{th}$ with $M_Q/T$ is found, studying the evolution with mass of $D_s(T)$ to better assess the comparison to lQCD calculations. Charm quark $D_s(T)$ is about $50\%$ larger than the asymptotic value for $M_Q\rightarrow \infty$, while bottom $D_s(T)$ is only $20\%$ higher. Such a behaviour entails for $M_Q\rightarrow \infty$, a $D_s(T)$ which is consistent within the current uncertainty to the most recent lattice QCD calculations with dynamical quarks and allows to envisage for bottom quark a thermalization time smaller than the one from $M_Q/T$ scaling.
[1] X. Dong and V. Greco, Prog. Part. Nucl. Phys. 104 (2019), 97-141.
[2] R. Rapp, P. B. Gossiaux, A. Andronic, R. Averbeck, S. Masciocchi, A. Beraudo, E. Bratkovskaya, P. Braun- Munzinger, S. Cao and A. Dainese, et al., Nucl. Phys. A 979, 21-86 (2018).
[3] M.L.Sambataro, V. Minissale, S. Plumari and V. Greco, e-Print: 2304.02953 (PLB submitted).
[4] M.L.Sambataro, Y, Sun, V. Minissale, S.Plumari and V.Greco, Eur.Phys.J.C 82 (2022) 9, 833 .
| Category | Theory |
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