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Pushing the hybrid approach to low beam energies with dynamic initial conditions from hadronic transport

Renan Góes-Hirayama1,2,3, Joscha Egger3, Zuzana Paulínyová2,3,4, Iurii Karpenko5, and Hannah Elfner6,1,2,3

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Phys. Rev. C 113, 044906 – Published 10 April, 2026

DOI: https://doi.org/10.1103/w87d-ps6f

Abstract

While hybrid approaches of relativistic hydrodynamics+transport have been well established for the dynamical description of heavy-ion collisions at high beam energies, moving to lower beam energies is challenging. In this work, we propose dynamic initial conditions for the viscous hydrodynamic evolution in heavy-ion collisions at low to intermediate beam energies. They are comprised of core hadrons based on the local energy density during the preequilibrium hadronic evolution. The smash-vhlle hybrid approach is then applied to lower beam energies, achieving good agreement with measured bulk observables between sNN=3 and 9.1GeV, thus providing theoretical guidance for the Beam Energy Scan performed by the STAR Collaboration at RHIC and the future Compressed Baryonic Matter experiment at GSI.

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Phys. Rev. C 113, 044906– Published 10 April, 2026
  • Received 7 October 2025
  • Revised 15 January 2026
  • Accepted 6 March 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.

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