https://doi.org/10.1140/epjc/s10052-022-10894-w
Regular Article - Theoretical Physics
The high-density equation of state in heavy-ion collisions: constraints from proton flow
1
Frankfurt Institute for Advanced Studies, Ruth-Moufang-Str. 1, 60438, Frankfurt am Main, Germany
2
Institute for Nuclear Theory, University of Washington, Box 351550, 98195, Seattle, WA, USA
3
Akita International University, Yuwa, 010-1292, Akita-city, Japan
4
Lawrence Berkeley National Laboratory, 1 Cyclotron Road, 94720, Berkeley, CA, USA
5
Institut für Theoretische Physik, Goethe Universität Frankfurt, Max-von-Laue-Str. 1, 60438, Frankfurt am Main, Germany
6
GSI Helmholtzzentrum für Schwerionenforschung GmbH, Planckstr. 1, 64291, Darmstadt, Germany
7
Helmholtz Research Academy Hesse for FAIR (HFHF), GSI Helmholtzzentrum für Schwerionenforschung GmbH, Campus Frankfurt, Max-von-Laue-Str. 12, 60438, Frankfurt am Main, Germany
a
steinheimer@fias.uni-frankfurt.de
Received:
7
September
2022
Accepted:
7
October
2022
Published online:
13
October
2022
A set of different equations of state is implemented in the molecular dynamics part of a non-equilibrium transport simulation (UrQMD) of heavy-ion collisions. It is shown how different flow observables are affected by the density dependence of the equation of state. In particular, the effects of a phase transition at high density are explored, including an expected reduction in mean 
. We also show that an increase in 
is characteristic for a strong softening of the equation of state. The phase transitions with a low coexistence density, 
, show a distinct minimum in the slope of the directed flow as a function of the beam energy, which would be a clear experimental signal. By comparing our results with experimental data, we can exclude any strong phase transition at densities below 
.
© The Author(s) 2022
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3. SCOAP3 supports the goals of the International Year of Basic Sciences for Sustainable Development.
