QM 2022

New experimental frontiers in the study of many-body nuclear interactions with ALICE

6 Apr 2022, 15:00

20m

small aula (Auditorium Maximum UJ)

Oral presentation Strongly coupled systems Parallel Session T08: Strongly coupled systems

Speaker

Raffaele Del Grande (Technische Universitaet Muenchen (DE))

Description

Exploring the strong interaction among hadrons, the ALICE Collaboration has for the first time extended the experimental measurements from two- to three-body interactions. These measurements provide unique information on many aspects of strongly-coupled systems, like the genuine three-body interaction, the formation of light nuclei and the search for exotic bound states. Among those, many-body interactions, also including hyperons, are an important ingredient in the calculation of the equation of state of neutron stars.

The results presented in this talk are obtained using high-multiplicity pp collisions at $\sqrt{s}$ = 13 TeV measured by ALICE at the LHC. The first measured three-body correlations include p-p-p and p-p-$\mathrm{\Lambda }$. Their genuine three-body interactions are obtained by subtracting the known two-body effects from the measured correlation functions for the triplets. In both systems, a non-zero three-particle cumulant is observed, providing a hint to the existence of a genuine three-body effect. Another class of many-body interaction studies is identified in the correlations of hadrons with light nuclei. ALICE has measured proton-deuteron (p-d) interactions, a system containing three hadrons building up a pair of a hadron and a nucleus. The experimental correlation function is compared with theoretical predictions obtained employing the scattering parameters extracted from traditional scattering experiments for the p-d system. A clear deviation is observed, which may be interpreted as a demonstration of the late formation time of (anti)deuterons in hadron-hadron collisions.

Presentation materials

Talk_QM2022_DelGrande_v4.pdf