Beauty-jet production in small systems with the ALICE experiment The production of heavy-flavor jets in proton-proton collisions serves as a fundamental test of perturbative QCD, while p-Pb (Pb-Pb) measurements provide information about the effects of the cold (and hot) nuclear matter. Our group plays a key role in several experimental measurements within the ALICE Heavy Flavor Jets and Correlations physics analysis group [1]. One such analysis is the measurement of the b-jet production at √s=5 TeV in pp and p-Pb collisions. The final results on the production cross-section and b-jet fractions in both systems, as well as the nuclear modification factor in p-Pb collisions (Fig. 1), have been submitted for publication [2]. With the excellent particle tracking capabilities of ALICE detector, these results extend to unprecedentedly low momenta (10 GeV/c) and pave the way to the understanding of flavor-dependent jet fragmentation as well as nuclear modification.

Development of the Muon Identification Detector for ALICE 3 The ALICE Collaboration is preparing its next major upgrade, ALICE 3, a future detector concept designed to fully exploit the physics potential of high-luminosity heavy-ion collisions at the CERN Large Hadron Collider. With significantly improved precision, tracking, and particle identification capabilities, ALICE 3 will open new possibilities for studying the quark-gluon plasma and the production of heavy-flavor hadrons [1]. A central component of this program is the Muon Identification Detector (MID), which enables detailed measurements via muonic decay channels. Muons provide a clean and penetrating probe, making them particularly well suited for investigating both open and hidden heavy-flavor states. Through these measurements, ALICE 3 aims to explore exotic hadrons and gain deeper insight into the microscopic dynamics of strongly interacting matter under extreme conditions.

Investigating the underlying event with identified leading processes The event-activity differential investigation of particle production reveals the connection between the leading process and the underlying event. It allows for the study of semi-soft vacuum-QCD effects potentially responsible for collectivity in events with higher activity, such as multiple-parton interactions (MPI). Flavor-dependent studies of these mechanisms can help separate color-charge and mass effects in jet production and fragmentation [1]. We conduct an ALICE measurement of the transverse event-activity dependent D0 meson production.

Particle production as a function of the underlying event The event-activity differential investigation of particle production reveals the connection between the leading process and the underlying event. It allows for the study of semi-soft vacuum-QCD effects potentially responsible for collectivity in events with higher activity, such as multiple-parton interactions (MPI). We investigated the production of charged particles associated with high-pT trigger particles at midrapidity in proton-proton collisions at √s=5.02 TeV in simulations, in function of RT, which is sensitive to multiple-parton interactions (MPI). We point out a correlation between RT and the leading pT, caused by triggered samples being biased toward events with gluon-radiation. We also propose a refined event classifier, RT,min, defined in the ‘transverse-min’ region (Fig. 1) that reduces contributions from initial- and final-state radiations of the main partonic scattering [1].

Sudden increase in the degrees of freedom in dense QCD matter One of the main challenges in high energy heavy-ion collisions is to simultaneously determine the temperature and the energy density of the matter produced in a collision, and hence the number of thermodynamic degrees of freedom (DOF). We presented the extraction of the temperature by analyzing the charged particle transverse momentum spectra in lead-lead and proton-proton collisions at LHC energies from the ALICE Collaboration using the Color String Percolation Model (CSPM). From the measured energy density (ε) and the temperature (T) the dimensionless quantity ε/T4 is obtained to get the degrees of freedom of the deconfined phase. We observe for the first time a two-step behavior in the increase of DOF, characteristic of deconfinement, above the hadronization temperature, at a temperature ~210 MeV for both Pb-Pb and pp collisions, and a sudden increase of the DOF to the ideal gas value of ~47 corresponding to three quark flavors in the case of Pb-Pb collisions [1].

Scaling properties of light and heavy-flavor jets We studied the structure of jets in proton-proton collisions at LHC energies using Monte Carlo simulations. We demonstrate that the radial jet profiles exhibit scaling properties with charged- hadron event multiplicity over a broad transverse-momentum range. Based on statistically motivated parametrizations of the jet profiles, we proposed that the scaling behavior stems from fundamental statistical properties of jet fragmentation. We also observed that the charged-hadron multiplicity distributions scale with jet momentum (Fig. 1). This suggests that the Koba–Nielsen–Olesen (KNO) scaling holds within a jet. The in-jet scaling is fulfilled without MPI, but breaks down in case MPI is present without color reconnection. Our findings imply that KNO scaling is violated by parton shower or multiple-parton interactions in higher-energy collisions [1].

Detection of forward protons and the study of central exclusive production. Central exclusive production (CEP) in proton–proton collisions provides a uniquely clean environment to study nonperturbative QCD dynamics, as the interacting protons remain intact and the centrally produced system is separated by large rapidity gaps. In such processes, the exchange of colorless objects—typically modeled as pomerons—dominates, making CEP particularly sensitive to diffractive mechanisms and multi-pomeron interactions (Fig. 1). The detection of forward protons is therefore essential, as it allows full kinematic reconstruction of the event and strong background suppression. Dedicated forward detectors, such as the TOTEM Roman Pot detectors, play a crucial role in enabling these measurements.

Development of a novel Proton CT device We participate in the Bergen pCT collaboration, formed for the development of a sampling calorimeter to be used for imaging in cancer therapy. Irradiation of cancer tumors using well-focused hadron beams can be a very effective treatment as the patient receives less unnecessary dose, thus allowing for a deposit of high destructive dose close to the critical organs. Most commonly proton beams are used, but there are investigations with heavier hadrons like Helium [16]. The ALPIDE calorimeter (Fig. 1) is based on the silicon pixel detector developed for the upgrade of the Inner Tracking System of ALICE. We have estimated the performance of the detector design using Monte Carlo simulations [1]. The ALPIDE detectors are already being produced and tested, and the group is currently working on the last refinements of the electronics and mechanics.