1. Collective observables probing the high density EoS
In this workshop collective observables as probes of the dense nuclear Equation-of-State (EoS) in heavy-ion collisions will be discussed. A systematic approach to analyzing stopping and directed flow phenomena, sensitive to density effects in nuclear matter, will be essential for understanding the EoS at high densities. Additionally, flow measurements for protons and light nuclei yield significant insights into the EoS. Higher order flow harmonics and their correlations can provide a stronger sensitivity than the traditional directed and elliptic flow components. Complementary information can be gathered from measuring the flow of pions, kaons, and hypernuclei, while proton-proton femtoscopy offers detailed access to baryon density. Dilepton production and dilepton flow during the hot and dense phase of the collision, are further promising observables that provide information across different stages of the collision. A systematic scan of flow across system sizes (e.g., Au+Au, Ag+Ag, Sn+Sn, C+C), and beam energies will further support constraining the high density EoS. This offers the opportunity for collaboration towards other accelerator facilities probing slightly lower energies, e.g. at FRIB, or slightly higher energies, e.g. RHIC. These observables offer a powerful toolkit for refining our understanding of dense baryonic matter.
2. Theoretical modelling of the EoS:
Advances in theoretical modeling are essential for accurately interpreting the aforementioned collective observables. This workshop will address the long standing discussion on the momentum dependence in the EoS, which plays a major role for flow and stopping observables and thus has implications for constraining the high density EoS. The latest developments in hydrodynamic and transport models will be explored, including single- and multi-fluid hydrodynamics, which are capable of capturing essential dynamical features of heavy-ion collisions at large densities. Transport approaches will be examined alongside Bayesian inference techniques to rigorously quantify EoS uncertainties. Additionally, symmetry energy effects will be assessed for their potential to enhance model precision, aiming to align theoretical predictions with experimental observables and improve overall the EoS characterization.
3. Multi-messenger studies of the EoS:
Multi-messenger astrophysics offers critical insight into the EoS by linking neutron star observations with heavy-ion collision experiments. Observables such as neutron star mass-radius relations provide direct constraints on the EoS and are essential for both the astrophysical and the nuclear context. This workshop will explore these connections, discussing recent results from gravitational wave detections, insights from NICER mass-radius measurements, and new information from hadron physics, particularly regarding the flow of light nuclei and hypernuclei. These multi-messenger approach provides an important mixture of synergetic observables for understanding dense nuclear matter and the connections between nuclear physics and astrophysics.
4. Data compilation:
An integral part of the workshop will focus on data standardization and compilation for EoS studies. We propose establishing a continuous, accessible database for experimental data on bulk observables, including flow measurements across system sizes, energies, and particle species. Alongside this, theoretical predictions regarding particle production and flow phenomena will be compiled, providing a centralized reference for EoS modeling efforts. This effort will not only promote transparency and reproducibility in EoS research but also create a valuable resource to support future experimental and theoretical studies.
