Particle Physics Seminar: Proton-proton hyper-tritons, and the origin of nuclei in hadronic collisions

Zoom: https://tau-ac-il.zoom.us/j/82556452816?pwd=U0ZyT1YwUHQzVXhIWWFnc1k5cXZwUT09

Abstract:

The production of nuclei (deuterons, He3, He4, …) at the LHC has a puzzling feature. Nuclei yields are consistent with a simple thermal Boltzman factor, with the same temperature parameter that describes mesons and nucleons. Altogether this thermal fit covers 9 orders of magnitude in yield. This is surprising: how can a deuteron with a binding energy of 2.2 MeV, participate in a thermal distribution in the state formed in heavy-ion collisions, which has characteristic particle energies of 100 MeV? Perhaps worse, given the deuteron charge radius of 2.1 fm, how can it participate in a thermal state in proton-proton collisions with coherence length of just 1-2 fm? I will explain how quantum mechanics offers a simple, elegant, and model-independent resolution of this puzzle, via nuclear coalescence. A key prediction of this idea concerns hyper-tritons, which take the fluffiness of deuterons to a whole other level, and for which new crucial experimental data from proton-proton collisions has finally recently become available.

Seminar Organizer: Dr. Michael Geller