The production of prompt D⁰, D⁺, and D^*+ mesons was measured at midrapidity (|y| < 0.5) in Pb–Pb collisions at the centre-of-mass energy per nucleon–nucleon pair $$ \sqrt{s_{\mathrm{NN}}} $$s NN = 5.02 TeV with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decay channels and their production yields were measured in central (0–10%) and semicentral (30–50%) collisions. The measurement was performed up to a transverse momentum (p_T) of 36 or 50 GeV/c depending on the D meson species and the centrality interval. For the first time in Pb–Pb collisions at the LHC, the yield of D⁰ mesons was measured down to p_T = 0, which allowed a model-independent determination of the p_T-integrated yield per unit of rapidity (dN/dy). A maximum suppression by a factor 5 and 2.5 was observed with the nuclear modification factor (R_AA) of prompt D mesons at p_T = 6–8 GeV/c for the 0–10% and 30–50% centrality classes, respectively. The D-meson RAA is compared with that of charged pions, charged hadrons, and J/ψ mesons as well as with theoretical predictions. The analysis of the agreement between the measured R_AA, elliptic (v₂) and triangular (v₃) flow, and the model predictions allowed us to constrain the charm spatial diffusion coefficient D_s. Furthermore the comparison of R_AA and v₂ with different implementations of the same models provides an important insight into the role of radiative energy loss as well as charm quark recombination in the hadronisation mechanisms.

A Large Ion Collider Experiment (ALICE) has been conceived and constructed as a heavy-ion experiment at the LHC. During LHC Runs 1 and 2, it has produced a wide range of physics results using all collision systems available at the LHC. In order to best exploit new physics opportunities opening up with the upgraded LHC and new detector technologies, the experiment has undergone a major upgrade during the LHC Long Shutdown 2 (2019–2022). This comprises the move to continuous readout, the complete overhaul of core detectors, as well as a new online event processing farm with a redesigned online-offline software framework. These improvements will allow to record Pb-Pb collisions at rates up to 50 kHz, while ensuring sensitivity for signals without a triggerable signature.

The interaction of $$\textrm{K}^{-}$$K - with protons is characterised by the presence of several coupled channels, systems like $${\overline{\textrm{K}}}^0$$K ¯ 0 n and $$\uppi \Sigma $$π Σ with a similar mass and the same quantum numbers as the $$\textrm{K}^{-}$$K - p state. The strengths of these couplings to the $$\textrm{K}^{-}$$K - p system are of crucial importance for the understanding of the nature of the $$\Lambda (1405)$$Λ ( 1405 ) resonance and of the attractive $$\textrm{K}^{-}$$K - p strong interaction. In this article, we present measurements of the $$\textrm{K}^{-}$$K - p correlation functions in relative momentum space obtained in pp collisions at $$\sqrt{s}~=~13$$s = 13 Te, in p–Pb collisions at $$\sqrt{s_{\textrm{NN}}}~=~5.02$$s NN = 5.02 Te, and (semi)peripheral Pb–Pb collisions at $$\sqrt{s_{\textrm{NN}}}~=~5.02$$s NN = 5.02 Te. The emitting source size, composed of a core radius anchored to the $$\textrm{K}^{+}$$K + p correlation and of a resonance halo specific to each particle pair, varies between 1 and 2 fm in these collision systems. The strength and the effects of the $${\overline{\textrm{K}}}^0$$K ¯ 0 n and $$\uppi \Sigma $$π Σ inelastic channels on the measured $$\textrm{K}^{-}$$K - p correlation function are investigated in the different colliding systems by comparing the data with state-of-the-art models of chiral potentials. A novel approach to determine the conversion weights $$\omega $$ω , necessary to quantify the amount of produced inelastic channels in the correlation function, is presented. In this method, particle yields are estimated from thermal model predictions, and their kinematic distribution from blast-wave fits to measured data. The comparison of chiral potentials to the measured $$\textrm{K}^{-}$$K - p interaction indicates that, while the $$\uppi \Sigma $$π Σ – $$\textrm{K}^{-}$$K - p dynamics is well reproduced by the model, the coupling to the $${\overline{\textrm{K}}}^0$$K ¯ 0 n channel in the model is currently underestimated.

Three-body nuclear forces play an important role in the structure of nuclei and hypernuclei and are also incorporated in models to describe the dynamics of dense baryonic matter, such as in neutron stars. So far, only indirect measurements anchored to the binding energies of nuclei can be used to constrain the three-nucleon force, and if hyperons are considered, the scarce data on hypernuclei impose only weak constraints on the three-body forces. In this work, we present the first direct measurement of the p–p–p and p–p– $$\Lambda $$Λ systems in terms of three-particle correlation functions carried out for pp collisions at $$\sqrt{s} = 13$$s = 13 TeV. Three-particle cumulants are extracted from the correlation functions by applying the Kubo formalism, where the three-particle interaction contribution to these correlations can be isolated after subtracting the known two-body interaction terms. A negative cumulant is found for the p–p–p system, hinting to the presence of a residual three-body effect while for p–p– $$\Lambda $$Λ the cumulant is consistent with zero. This measurement demonstrates the accessibility of three-baryon correlations at the LHC.

The first measurement of the production of pions, kaons, (anti-)protons and $$\phi $$ϕ mesons at midrapidity in Xe–Xe collisions at $$\sqrt{s_{\mathrm{NN}}} = 5.44~\text {TeV}$$sNN=5.44TeV is presented. Transverse momentum ( $$p_{\mathrm{T}}$$pT ) spectra and $$p_{\mathrm{T}}$$pT -integrated yields are extracted in several centrality intervals bridging from p–Pb to mid-central Pb–Pb collisions in terms of final-state multiplicity. The study of Xe–Xe and Pb–Pb collisions allows systems at similar charged-particle multiplicities but with different initial geometrical eccentricities to be investigated. A detailed comparison of the spectral shapes in the two systems reveals an opposite behaviour for radial and elliptic flow. In particular, this study shows that the radial flow does not depend on the colliding system when compared at similar charged-particle multiplicity. In terms of hadron chemistry, the previously observed smooth evolution of particle ratios with multiplicity from small to large collision systems is also found to hold in Xe–Xe. In addition, our results confirm that two remarkable features of particle production at LHC energies are also valid in the collision of medium-sized nuclei: the lower proton-to-pion ratio with respect to the thermal model expectations and the increase of the $$\phi $$ϕ -to-pion ratio with increasing final-state multiplicity.