The production mechanism of light (anti-)nuclei in high-energy collisions remains an open question in the physics community. From a macroscopic perspective, the observed yields are effectively described by a thermal production, with statistical hadronization models providing an excellent description over several orders of magnitude in heavy-ion collisions. However, the applicability of such models to small collision systems, such as proton–proton collisions, is still under debate. In this context, a variety of microscopic approaches, most notably those based on nucleon coalescence, have been proposed to describe light-nuclei formation.

In this seminar, recent ALICE results addressing this problem will be discussed. Measurements based on pion–deuteron correlations will be presented, demonstrating the significant role of nucleonic resonances in deuteron production. In particular, the Δ decay peak observed in pion–proton correlations has now been clearly seen in deuteron–pion correlations. A careful examination of the different production hypotheses has revealed that the only plausible explanation is a deuteron being produced following the decay of the Δ resonance, involving the fusion of the daughter nucleon of the Δ with another nearby nucleon. Further, a discussion will be provided on the compatibility of this hypothesis with previous ALICE correlation measurements involving deuterons.