The high-density equation of state in heavy-ion collisions: constraints from proton flow

Journal Article · 12 October 2022 · European Physical Journal. C, Particles and Fields (Online)

DOI: https://doi.org/10.1140/epjc/s10052-022-10894-w · OSTI ID:1892118

Steinheimer, Jan; Motornenko, Anton; Sorensen, Agnieszka; Nara, Yasushi; Koch, Volker; Bleicher, Marcus

Abstract 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 $$$$m_T$$$$ $m_T$ . We also show that an increase in $$$$v_2$$$$ $v_2$ is characteristic for a strong softening of the equation of state. The phase transitions with a low coexistence density, $$$$n_{\text {CE}}<4 n_0$$$$ $n_{\text{CE}}<4n_0$ , show a distinct minimum in the slope of the directed flow as a function of the beam energy, which would be a clear experimental signal. By comparing our results with experimental data, we can exclude any strong phase transition at densities below $$$$4n_0$$$$ $4n_0$ .

• Research Organization: Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Univ. of Washington, Seattle, WA (United States)
• Sponsoring Organization: JSPS KAKENHI; USDOE; USDOE Office of Science (SC), Nuclear Physics (NP)
• Grant/Contract Number: AC02-05CH11231; FG02-00ER41132
• OSTI ID: 1892118
• Journal Information: European Physical Journal. C, Particles and Fields (Online), Journal Name: European Physical Journal. C, Particles and Fields (Online) Journal Issue: 10 Vol. 82; ISSN 1434-6052
• Publisher: Springer Science + Business MediaCopyright Statement
• Country of Publication: Germany
• Language: English