NuclearConfectionery: Multi-stage Simulation Framework for Modeling Relativistic Heavy-ion Collisions

Abstract

We present the NuclearConfectionery, a modular framework for simulating the full dynamical evolution of relativistic heavy-ion collisions. Its core hydrodynamic module, CCAKE 2.0, represents a major advance over previous SPH-based relativistic hydrodynamic codes. CCAKE 2.0 simultaneously evolves energy-momentum and multiple conserved charges (B, S, Q) with a four-dimensional equation of state, and can be run in either Cartesian or hyperbolic coordinates, enabling consistent simulations from the RHIC Beam Energy Scan to LHC energies. We have implemented a particlization module that supports global BSQ charge conservation on the freeze-out surface; the resulting hadron ensemble is then propagated through a hadronic transport afterburner. A source term is included in the equations of motion to couple jets to the fluid, allowing simultaneous bulk and hard-probe evolution or, alternatively, for stopped baryons at low beam energies. The framework offers flexible choices of equations of motion (Israel-Stewart, DNMR, ADNH) and transport coefficients, along with GPU-ready performance via Kokkos/Cabana, offline equation of state inversion for 4D tables, and containerized portability. We validate the code with semi-analytical benchmarks (including BSQ Gubser and Landau-Khalatnikov solutions) and extensive convergence studies. The NuclearConfectionery provides a user-friendly, high-performance, open-source tool for event-by-event simulations across collision energies, offering flexibility to study QCD matter at both vanishing and finite densities.