Speaker
Description
The creation of loosely bound light (anti-)(hyper-)nuclei in heavy ion collisions near the phase transition temperature (Tch≈155 MeV) has been a puzzling observation. We solve this puzzle by showing that the light cluster abundancies in heavy ion reactions stay approximately constant from chemical freeze-out to kinetic freeze-out. To this aim we develop an extensive network of coupled reaction rate equations including stable hadrons and hadronic resonances to describe the temporal evolution of the abundancies of light (anti-)(hyper-)nuclei in the late hadronic environment. It is demonstrated that the chemical equilibration of the light nuclei occurs on a very short timescale as a consequence of the strong production and dissociation processes. However, because of the partial chemical equilibrium of the stable hadrons the abundancies of the light nuclei stay nearly constant during the evolution and cooling of the hadronic phase. A quantitative analysis shows a nice agreement with experimental data of the ALICE collaboration on d, 3 He, HΛ3 , and 4 He yields for a very broad range of temperatures at T≲155 MeV.This solves the longstanding contradiction between the thermal fits and the late stage coalescence.
| Topic | Heavy Ion Physics |
|---|
