Hunting three-body forces

ongoing

HUNTING-3BFs aims to solve the many-body problem in nuclear physics. This would allow describing the properties of nuclear matter starting from the interaction among the constituents and to extrapolate its behaviour in dense environments in the Universe, like in the innermost region of neutron stars. The main difficulties in the current state-of-the-art many-body calculations arise from complex effects induced by long-range Coulomb interactions, which are challenging to predict, and from the emergence of short-range three-body nuclear forces (3BFs) in the dynamics of hadrons, which have been never anchored to direct experimental measurements. The primary goal of this project is to quantify for the first time these effects using new three-body scattering measurements. The latter will be performed using the femtoscopy method at the Large Hadron Collider (LHC). The final state interaction of p-p-p and p-p-Λ triplets as well as p-d and Λ-d pairs emitted in pp collisions at the LHC will be measured with the ALICE detector using correlation functions. The sensitivity to the contribution of 3BFs will be reached with the full statistics of the LHC Run 3 data taking (2022-2026). The PI will deliver phenomenological potentials for the NNN and NNΛ 3BFs, by constraining the models to experimental correlation functions. To reach this goal the PI will develop a framework capable of solving numerically the three-body problem. One of the main novelties of HUNTING-3BFs is the study of the interactions as a function of the energy and distance, giving a unique chance to probe different interaction ranges. This project will provide a new groundbreaking method to solve the many-body problem in nuclear physics with strong impact on research areas ranging from the domain of nuclear physics to astrophysics.