Speaker
Description
Light-nuclei production in relativistic heavy-ion collisions is simulated within an updated Three-fluid Hydrodynamics-based Event Simulator Extended by UrQMD (Ultra-relativistic Quantum Molecular Dynamics) final State interactions (THESEUS). The simulations are performed in the collision energy range of โsNN=3โ19.6 GeV. The advantage of a generator is that the light-nuclei are produced within the thermodynamical approach on an equal basis with hadrons, while other existing models use the coalescence mechanism with fitting parameters. Since the light nuclei do not participate in the UrQMD evolution, the only additional parameter related to the light nuclei, i.e., the energy density of late freeze-out, is used for the imitation of the afterburner stage of the collision. The updated THESEUS provides a reasonable reproduction of data on bulk observables of the light nuclei, especially their functional dependence on the collision energy and light-nucleus mass. Various ratios, d/p, t/p, t/d, and N(t)รN(p)/N2(d), are also considered. Imperfect reproduction of the light-nuclei data leaves room for medium effects in produced light nuclei. The directed flow of different particles including light-nuclei, is calculated, ant at low energies (3GeV) it gives much more better results than at higher energies.
