報告題目：The QCD equation of state from Heavy ion collisions and neutron star mergers

　　報告人：Dr. Jan Steinheimer-Froschauer (Frankfurt Institute for Advanced Studies (FIAS))

　　時間：7月11日（星期三）15:00-16:00

　　地點：1-401

　　報告內容：

　　The properties of dense and hot nuclear matter are currently investigated in disparate physical environments. Neutron stars, their mergers, and core-collapse supernovae explore matter at densities several times that of nuclear saturation, characterized by a high asymmetry in isospin and zero to low temperatures. At the same time in laboratories, the equation of state of almost isospin symmetric matter can be studied with the collisions of heavy nuclei at low to ultra-relativistic energies. While these macroscopic astrophysical objects and microscopic collision systems at wildly different beam energies, seem to be disjoint, in fact they all can be seen as part of the major remaining challenge in the study of the strong interaction, i.e. to map out the phase diagram of QCD in terms of temperature and net baryon density. In this seminar I will present the current status of our knowledge on the equation of state of dense QCD matter in neutron stars as well as from heavy ion reactions. This also includes some of our recent results on using statistical inference to constrain the high density part of the equation of state with the best currently available flow data in heavy ion reactions. From these results the current shortcomings in experimental data and microscopic modelling will become apparent. The latter part of the seminar I will discuss how the finite temperature regions of the QCD phase diagram can be studied simultaneously with heavy ion reactions in the sub-2 GeV beam energy range, available in the future accelerator facilities and binary neutron star mergers as well as core-collapse supernovae. Here, it is important to discuss similarities but also differences, for example in the isospin composition of the system and how these differences can be overcome to arrive at a firm conclusion on the nature of dense nuclear matter. Finally, the seminar will address open problems and propose potential solutions for incorporating microscopic simulations of heavy ion reactions into future statistical analyses of the dense QCD equation of state.。

　　報告人簡介：

　　Jan Steinheimer，法蘭克福高等研究院研究員。2011年在法蘭克福大學獲得理論物理博士學位，2011-2012年德國法蘭克福高等研究院博士后，2012-2013年美國勞倫斯伯克利國家實驗室博士后，2013-2017年德國法蘭克福高等研究院博士后。長期致力于重離子碰撞理論研究，在流體動力學、非平衡相變、熱密核物質狀態方程、人工智能和深度學習在基礎研究，尤其是在核物理中的應用等領域有著豐富的研究成果。已在Phys. Rev. Lett., JHEP，Phys. Lett. B, Phys. Rev. C, Phys. Rev. D, Eur. Phys. J. C，Prog. Part. Nucl. Phys.等學術刊物上發表SCI論文110余篇，H因子37。