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One of the present challenge for the theoretical understanding of heavy-quark hadronization is represented by the description of the measurements of heavy hadron production in pp, pA and AA collisions from RHIC to top LHC energies. The Λc/D0 ratio observed in AA collisions has a value of the order of the unity, and experimental measurements in pp collisions at both √S = 5.02 TeV and √S = 13 TeV have shown ratios for charm baryons Λc,Ξc0 and Ωc0 respect to D0 meson larger than that measured and expected in e+e−, ep collisions. We present an hadronization mechanism based on the coalescence and fragmentation processes, and the results obtained in AA collisions for D0 and Λc. related baryon to meson ratios at RHIC and LHC. We present moreover results obtained for the charmed hadron production in pp collisions at LHC energies assuming the formation of an hot QCD matter at finite temperature.We calculate the heavy baryon/meson ratio and the pT spectra of charmed hadrons D0. Λc0 and the recently measured Ξc baryon, finding an enhancement in comparison with the ratio observed for e+e−, ep collisions; with this approach we also predict a significant production of Qc.

We study the propagation of heavy quarks (HQs) in the quark-gluon plasma (QGP) by means of a relativistic Boltzmann transport (RBT) approach. The non-perturbative interaction between heavy quarks and light quarks is described by means of a quasi-particle approach able to describe simultaneously the experimental data for the nuclear suppression factor $R_{\rm AA}$ and the elliptic flow $v_2(p_T)$ of D mesons from RHIC to LHC energies. In the same framework we predict the B meson nuclear modification factor at LHC. Finally, we discuss the relevance of initial state fluctuations that allows to extend the analysis to high order anisotropic flows $v_n(p_T)$ as well as to investigate the role of QCD interaction in developing correlations between the light and the heavy flavour anisotropic flows., Comment: 27th International Conference on Ultrarelativistic Nucleus-Nucleus Collisions (Quark Matter 2018)

The recent experimental measurements on $pp$ collisions at $\sqrt{s}=5.02 \,\rm TeV$ have shown a very large abundance of heavy baryon production corresponding to a ratio of $\Lambda_c/D^0 \sim 0.6$, about one order of magnitude larger than what measured in $e^+e^-$, $ep$ collisions and even in $pp$ collisions at LHC, but at forward rapidity. We apply for the first time to $pp$ collisions a quark coalescence plus fragmentation approach developed for $AA$ collisions, assuming the formation of Hot QCD matter at finite temperature. An approach that has correctly predicted a $\Lambda_c/D \sim O(1)$ in AA collisions at RHIC energy. We calculate the heavy baryon/meson ratio and the $p_T$ spectra of charmed hadrons with and without strangeness content: $D^{0}$, $D_{s}$, $\Lambda_{c}^{+}$, $\Xi_c$ and $\Omega_c$ in $pp$ collisions at top LHC energies, finding a satisfactory result for the measured $\Lambda_{c}^{+}/D^0$ and the $\Xi_c/D^0$ without any specific tuning of parameters to $pp$ collisions. At variance with other approaches a coalescence approach predicts also a significant production of $\Omega_c$ such that $\Omega_c/D^0 \sim O(10^{-1})$ ., Comment: 8 pages, 5 figures; modifications in Figures 1,2,3,4,5 and corrected typos

We study the propagation of heavy quarks (HQs) in the quark-gluon plasma (QGP) by means of a event-by-event relativistic Boltzmann transport (RBT) approach. We discuss the correlations between light flavor and heavy quarks (HQs) flow harmonics and the relative fluctuations of anisotropic flows \(\sigma _{v_{n}}/\langle v_n \rangle \) Moreover, we investigate the role of QCD interaction in developing these flows correlations. As recently recognized, strong electro-magnetic (E.M.) fields are created in Ultra-relativistic Heavy-Ion Collision (HIC). We show that these fields are responsible for a splitting of directed flow \(v_1\) of D and anti-D mesons. Moreover, we discuss the effect of the initial large bulk vorticity on the build up of rapidity odd HQs directed flow \(v_1\).

The hadronization process of heavy hadrons with bottom and charm quarks, especially for baryons \(\varLambda _c\), in a dense QGP medium is largely not understood. We present predictions obtained with a coalescence plus fragmentation model, for \(D^0\), \(D_s\), \(\varLambda _c\) spectra, the related baryon to meson ratios and the \(D_s/D^0\) ratio, both at RHIC and LHC energies in a wide range of transverse momentum. We discuss how our model can naturally predict values of the order of O(1) for \(\varLambda _c/D^0\) as recently measured at both RHIC and LHC. Moreover assuming that at the LHC top energies there can be the formation of QGP, we show that in the same scheme due to considerable volume effect a still large \(\varLambda _c/D^0 \approx 0.5\) is predicted as seen by ALICE in pp collisions.

We describe the propagation of heavy quarks (HQs), charm and bottom, in the quark-gluon plasma (QGP) by means of a full Boltzmann transport approach including event-by-event fluctuations within a coalescence plus fragmentation hadronization. The non-perturbative dynamics of the interaction between HQs and plasma particles have been taken into account through a Quasi-Particle Model (QPM). We show that the resulting charm in-medium evolution is able to correctly predict simultaneously not only the experimental data for the average D-mesons RAA(pT) and v2,3(pT) at LHC energies but also the extension of the analysis to the event-shape engineeering tecnique that classify events according to magnitude of the second-order harmonic reduced flow vector q2. In the same scheme we show predictions for RAA(pT) of electrons from semi-leptonic B-mesons decays at top LHC energies. Our results entail a determination of Ds which is consistent with the lattice QCD calculations.

The hadronization process of heavy hadrons with bottom and charm quarks, especially for baryons Λ c and Λ b , in a dense QGP medium is largely not understood. We present within a coalescence plus fragmentation model the predictions for D 0, Ds, Λ c , B and Λ b spectra and the related baryon to meson ratios at RHIC and LHC in a wide range of transverse momentum region up to 10 GeV, moreover we show the effect of the hadronization mechanism which plays a fundamental role to describe simultaneously the experimental data for the nuclear suppression factor RAA and the elliptic flow υ 2(pT) of heavy hadrons from RHIC to LHC energies. In particular, we show the considerable change of the Nuclear modification factor of D mesons due to the large Ac production, explaining the RAA (pT) < 1 observed by STAR at low momenta. We will discuss how our model can naturally predict values of the order of O(1) for Λ c /D 0 as recently measured at both RHIC and LHC, and we present the novel predictions for Λ b /B not yet measured, which are much larger than the expectations from fragmentation. Moreover assuming that ar the LHC top energies there can be the formation of QGP, we show that in the same scheme due to considerable volume effect a still large Λ c /D 0 ≈ 0.5 is predicted as seen by ALICE in pp and pA collisions Furthermore in the same scheme can be predicted a baryon to meson ratio Λ c /D 0 in pp collisions assuming that at the LHC top energies there can be the formation of QGP matter. The results show a considerable volume effects that significantly reduce the ratios, but still predict quite larger values with respect to fragmentation, in agreement with recent data from ALICE in pp collisions.

We study the correlations between light flavor and heavy quarks (HQs) flow harmonics at LHC energy within a transport approach. We have investigated the role of transport coefficient in developing these anisotropic flows correlations. We suggest υ n h e a v y − υ n l i g h t correlation and the relative fluctuations of anisotropic flows συη /〈υn 〉 as novel observables to constrain the HQ transport coefficients in quark gluon plasma. Finally, very strong electro-magnetic (E.M.) fields are created in Ultra-relativistic Heavy-Ion Collision (HIC). We show within relativistic Boltzmann transport approach coupled with E.M. field that the strong e.m. field is responsible for a splitting of directed flow υ 1 of D and anti-D mesons of few percent, i.e. much larger compared to the observed charged particles. Moreover, we discuss the role played by the initial large bulk vorticity on the build up of rapidity odd HQs directed flow υ 1.

In a coalescence plus fragmentation approach we calculate the heavy baryon/meson ratio and the $p_T$ spectra of charmed hadrons $D^{0}$, $D_{s}$ and $\Lambda_{c}^{+}$ in a wide range of transverse momentum from low $p_T$ up to about 10 GeV and discuss their ratios from RHIC to LHC energies without any change of the coalescence parameters. We have included the contribution from decays of heavy hadron resonances and also the one due to fragmentation of heavy quarks which do not undergo the coalescence process. The coalescence process is tuned to have all charm quarks hadronizing in the $p_T\rightarrow 0$ limit and at finite $p_T$ charm quarks not undergoing coalescence are hadronized by independent fragmentation. The $p_T$ dependence of the baryon/meson ratios are found to be sensitive to the masses of coalescing quarks, in particular the $\Lambda_{c}/D^{0}$ can reach values of about $\rm 1\div 1.5 $ at $p_T \approx \, 3$ \mbox{GeV}, or larger, similarly to the light baryon/meson ratio like $p/\pi$ and $\Lambda/K$, however a marked difference is a quite weak $p_T$ dependence with respect to the light case, such that a larger value at intermediate $p_T$ implies a relatively large value also for the integrated yields. A comparison with other coalescence model and with the prediction of thermal model is discussed., Comment: 13 pages, 9 figures. Fig. 5 updated and some minor changes in the text

We study the propagation of charm quarks in the quark-gluon plasma (QGP) by means of a relativistic Boltzmann transport (RBT) approach. We have take into account for non-perturbative interaction between heavy quarks and light quarks by mean a quasi-particle approach. Such a model is able to catch the main features of non-perturbative interaction as the increasing of the interaction in the region of low temperature near $T_C$. The hadronization of charm quarks in $D$ mesons is described by mean of an hybrid model of fragmentation plus coalescence. We show that the resulting charm in-medium evolution is able to correctly predict simultaneously the experimental data for the nuclear suppression factor $R_{AA}$ and the elliptic flow $v_2(p_T)$at both RHIC and LHC energies at different centralities.

The drag and diffusion coefficients of heavy baryons ($\Lambda_c$ and $\Lambda_b$) in the hadronic phase created in the latter stage of the heavy-ion collisions at RHIC and LHC energies have been evaluated recently. In this work we compute some experimental observables, such as the nuclear suppression factor $R_{AA}$ and the elliptic flow $v_2$ of heavy baryons at RHIC and LHC energies, highlighting the role of the hadronic phase contribution to these observables, which are going to be measured at Run 3 of LHC. For the time evolution of the heavy quarks in the QGP and heavy baryons in the hadronic phase we use the Langevin dynamics. For the hadronization of the heavy quarks to heavy baryons we employ Peterson fragmentation functions. We observe a strong suppression of both the $\Lambda_c$ and $\Lambda_b$. We find that the hadronic medium has a sizable impact on the heavy-baryon elliptic flow whereas the impact of hadronic medium rescattering is almost unnoticeable on the nuclear suppression factor. We evaluate the $\Lambda_c/D$ ratio at RHIC and LHC. We find that $\Lambda_c/D$ ratio remain unaffected due to the hadronic phase rescattering which enable it as a nobel probe of QGP phase dynamics along with its hadronization., Comment: 22 pages, 15 figures

An hadronization model that includes coalescence and fragmentation is used in this work to obtain predictions at both RHIC and LHC energy for light and strange hadrons transverse momentum spectra (π , p , k , Λ) and baryon to meson ratios (p /π , Λ/k ) in a wide range of pT . This is accomplished without changing coalescence parameters. The ratios p /π and Λ/K shows the right behaviour except for some lack of baryon yield in a limited pT range around 6 GeV. This would indicate that the AKK fragmentation functions is too flat at pT < 8 GeV.

In a coalescence plus fragmentation approach we study the pT spectra of charmed hadrons D0, Ds up to about 10 GeV and the Λ+c /D0 ratio from RHIC to LHC energies. In this study we have included the contribution from decays of heavy hadron resonances and also that due to fragmentation of heavy quarks that are left in the system after coalescence. The pT dependence of the heavy baryon/meson ratios is found to be sensitive to the heavy quark mass. In particular we found that the Λc/D0 is much flatter than the one for light baryon/meson ratio like p/π and Λ/K.

We describe the propagation of Heavy quarks (HQs) in the quark-gluon plasma (QGP) within a relativistic Boltzmann transport (RBT) approach. The interaction between heavy quarks and light quarks is described within quasi-particle approach which is able to catch the main features of non-perturbative interaction as the increasing of the interaction in the region of low temperature near TC. In our calculations the hadronization of charm quarks in D mesons is described by mean of an hybrid model of coalescence plus fragmentation. We show that the coalescence play a key role to get a good description of the experimental data for the nuclear suppression factor RAA and the elliptic flow υ2(pT) at both RHIC and LHC energies. Moreover, we show some recent results on the direct flow υ1 and triangular flow υ3 of D meson.

In a coalescence plus independent fragmentation approach we calculate the ${p}_{T}$ spectra of the main hadrons: $\ensuremath{\pi},K,p,\overline{p},\mathrm{\ensuremath{\Lambda}},\ensuremath{\phi}$ in a wide range of transverse momentum from low ${p}_{T}$ up to about 10 GeV. The approach in its main features was developed several years ago at Relativistic Heavy Ion Collider (RHIC) energy. Augmenting the model with the inclusion of some more main resonance decays, we show that the approach correctly predicts the evolution of the ${p}_{T}$ spectra from RHIC to LHC (Large Hadron Collider) energy and in particular the baryon-to-meson ratios $p/\ensuremath{\pi},\overline{p}/\ensuremath{\pi},\mathrm{\ensuremath{\Lambda}}/K$ that reach a value of the order of unit at ${p}_{T}\ensuremath{\sim}3\phantom{\rule{0.16em}{0ex}}\mathrm{GeV}$. This is achieved without any change of the coalescence parameters. The more recent availability of experimental data up to ${p}_{T}\ensuremath{\sim}10\phantom{\rule{0.16em}{0ex}}\mathrm{GeV}$ for $\mathrm{\ensuremath{\Lambda}}$ spectrum as well as for $p/\ensuremath{\pi}$ and $\mathrm{\ensuremath{\Lambda}}/K$ shows some lack of yield in a limited ${p}_{T}$ range around 6 GeV. This indicates that the baryons ${p}_{T}$ spectra from Albino-Kniehl-Kramer fragmentation functions are too flat at ${p}_{T}\ensuremath{\lesssim}8\phantom{\rule{0.16em}{0ex}}\mathrm{GeV}$. We also show that in a coalescence plus fragmentation approach one predicts a nearly ${p}_{T}$ independent $p/\ensuremath{\phi}$ ratio up to ${p}_{T}\ensuremath{\sim}4\phantom{\rule{0.16em}{0ex}}\mathrm{GeV}$ followed by a significant decrease at higher ${p}_{T}$. Such a behavior is driven by a similar radial flow effect at ${p}_{T}l2\phantom{\rule{0.16em}{0ex}}\mathrm{GeV}$ and the dominance of fragmentation for $\ensuremath{\phi}$ at larger ${p}_{T}$.

We discuss the application of a phase-space coalescence plus fragmentation model for the hadronization of the quark-gluon plasma (QGP) created in ultra-relativistic heavy-ion collisions. Recombination of minijet partons with the partons from the QGP is also included and plays a role at pT ~ 2 – 4 GeV where the baryon to meson anomaly is observed experimentally. We show our prediction for light and strange hadrons transverse momentum spectra (π, p, k, Λ) and baryon to meson ratios (p/π, Λ/k) in a wide range of pT, both for RHIC and LHC energies. The baryon to meson ratio at LHC presents similar features of that at RHIC, but with a shift in the peak of about 0.5 GeV, and this is well predicted by our model.

We describe the propagation of charm quarks in the quark-gluon plasma (QGP) by means of an event-by-event transport approach. In our calculations the non-perturbative interaction between heavy quarks and light quarks has been taken into account through a quasi-particle approach with thermal light quark masses tuned to reproduce lQCD thermodynamics. We found that the flow observables $v_2$ and $v_3$ of D mesons are comparable with the experimental measurements for Pb+Pb collisions at 5.02 ATeV in different ranges of centrality selections. The results are analyzed with Event-Shape Engineering technique. The comparison of the anisotropic flow coefficients $v_n$ with experimental data show a quite well agreement with experimental data for different flow vector $q_2$ selections, which confirms the strong coupling between charm quarks and light quarks in the QCD matter. Furthermore, we present here a novel study of the event-by-event correlations between flow harmonics of $D$ mesons and soft hadrons at LHC energy with the Event-Shape Engineering technique that can put further constraints on heavy quark transport coefficients toward a solid comparison between the phenomenological determination and the lattice QCD calculations., 8 pages, 8 figures