by Pietro Antonioli. Published: 29 June 2015


The Italian community working on physics with heavy ions at the LHC convened last 26-27 May in Bologna in a workshop organized by the ALICE Bologna group in the historical venue of the Accademia delle Scienze in the city centre.

The meeting tried to improve the connections between the experimentalists, mainly working on ALICE, and the Italian theoreticians working in this field; a  group steadily growing during the last years.

The meeting was held as a workshop with a large fraction of the time devoted to discussion. In the workshop's web page there was the possibility to add material or submit questions and in that sense it has been very useful for organizing the agenda and the overall success of the meeting.

The workshop was organized along three sessions: soft physics, hard probes/ heavy flavour and a third one covering more exotic topics. Our colleagues from ALICE, Michele Floris, Francesco Prino and Eugenio Scapparone acted as conveners together with the theoreticians Francesco Beccattini, Andrea Beraudo and Antonio Polosa.

The meeting had more than 50 participants along the two days with a lively atmosphere and many interesting topics covered, with always in mind to develop the items with a simple and direct approach comprehensible from both sides, experimental and theoretical. The soft physics session discussed contributions related to the study of collective flow in extremely central collisions, the hydrodynamic code developed in Italy ECHO-QGP and some application of it as well as lattice calculations, a traditional field for Italian theoretical community. ALICE physicists presented analyses and ideas about the study of event-by-event fluctuations, evolution of the system size and particles yields. The intriguing evidence of collective phenomena already present in pp and p-Pb collisions was also intensively discussed.

The hard probes and heavy flavour session opened with a comprehensive overview of the measurements done during Run 1 for jets, open heavy flavour and quarkonia, led by ALICE physicists. It was then nice to see the spirit of the meetings at work with joint presentations by an experimentalist and a theoretician on RAA measurements on quarkonia and heavy flavour observables in smaller collisional systems. The latter talk presented also an application of the ECHO-QGP code presented in the first session. Other talks covered respectively correlations and the study of Multi Parton Interactions, always treated with the same approach having a pair of experimentalist and theoretician presenting the topic.

The last session, even if shorter, generated a lively discussion about the possibility to observe effects of magnetic fields generated in heavy-ion collisions,  test of binding models for exotic particles such X(3872) via observation of the deuteron spectra at high pT  and the use of ultra-peripheral interactions to check exotic production via the γγ -> γγ process.

The organizers intend to repeat the meeting on a yearly basis helping to shape future analysis and theoretical developments in a field where the research of new observables is critical, especially now with the foreseen better statistical precision foreseen during LHC Run 2 and with QGP studies entering a new era.