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 two-particle momentum correlation functions between charm mesons (${\mathrm{D}}^{*\pm }$ and ${\mathrm{D}}^{\pm }$) and charged light-flavor mesons (${\pi }^{\pm }$ and ${\mathrm{K}}^{\pm }$) in all charge combinations are measured for the first time by the ALICE Collaboration in high-multiplicity proton–proton collisions at a center-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$. For DK and ${\mathrm{D}}^{*}\mathrm{K}$ pairs, the experimental results are in agreement with theoretical predictions of the residual strong interaction based on quantum chromodynamics calculations on the lattice and chiral effective field theory. In the case of $\mathrm{D}\pi$ and ${\mathrm{D}}^{*}\pi$ pairs, tension between the calculations including strong interactions and the measurement is observed. For all particle pairs, the data can be adequately described by Coulomb interaction only, indicating a shallow interaction between charm and light-flavor mesons. Finally, the scattering lengths governing the residual strong interaction of the $\mathrm{D}\pi$ and ${\mathrm{D}}^{*}\pi$ systems are determined by fitting the experimental correlation functions with a model that employs a Gaussian potential. The extracted values are small and compatible with zero.

The production of prompt ${\mathrm{\Lambda }}_c^{+}$ baryons has been measured at midrapidity in the transverse momentum interval $0<p_T<1 \text{GeV}/c$ for the first time, in $pp$ and $p$–Pb collisions at a center-of-mass energy per nucleon-nucleon collision $\sqrt{s_{NN}}=5.02\text{TeV}$. The measurement was performed in the decay channel ${\mathrm{\Lambda }}_c^{+}\to p{K}_S^0$ by applying new decay reconstruction techniques using a Kalman-Filter vertexing algorithm and adopting a machine-learning approach for the candidate selection. The $p_T$-integrated ${\mathrm{\Lambda }}_c^{+}$ production cross sections in both collision systems were determined and used along with the measured yields in Pb–Pb collisions to compute the $p_T$-integrated nuclear modification factors $R_{p\mathrm{Pb}}$ and $R_{AA}$ of ${\mathrm{\Lambda }}_c^{+}$ baryons, which are compared to model calculations that consider nuclear modification of the parton distribution functions. The ${\mathrm{\Lambda }}_c^{+}/D^0$ baryon-to-meson yield ratio is reported for $pp$ and $p$–Pb collisions. Comparisons with models that include modified hadronization processes are presented, and the implications of the results on the understanding of charm hadronization in hadronic collisions are discussed. A significant ($3.7\sigma$) modification of the mean transverse momentum of ${\mathrm{\Lambda }}_c^{+}$ baryons is seen in $p$–Pb collisions with respect to $pp$ collisions, while the $p_T$-integrated ${\mathrm{\Lambda }}_c^{+}/D^0$ yield ratio was found to be consistent between the two collision systems within the uncertainties.