论文标题
NICA Energies的QCD相图：$ K^+/π^+$ horn效应和theseus中的光簇
QCD Phase Diagram at NICA energies: $K^+/π^+$ horn effect and light clusters in THESEUS
论文作者
论文摘要
我们讨论了基于三流体流体力学的程序Theseus开发的最新进展，用于适用于计划中的NICA和公平实验的中间能量的重型离子碰撞的事件发生器。我们遵循这样的策略，即在QCD相图中冻结表面的粒子分布的修改可以直接映射到突然的冷冻方案中可观察的粒子。我们报告了这些研究的首先结果，用于生产光簇（Deuterons和Tritons），这些结果可以与HADES和NA49实验的实验数据以及在$ K^+/π^+$比率的碰撞能量依赖性中观察到的“ Horn”效应的解释。 QCD相图中对光簇产生的中等影响在最高的NICA能量上可以忽略不计，但在最低能量下应起主要作用。当由pion化学电位建模的玻色凝结的发作会导致低动量（LHC能量在LHC能量上看到），并且在NICA能量范围内已经发生了尖锐的凝聚，可以获得$ k^+/π^+$比率中的尖锐的“喇叭”型信号。
We discuss recent progress in the development of the three-fluid hydrodynamics-based program THESEUS towards an event generator suitable for applications to heavy-ion collisions at the intermediate energies of the planned NICA and FAIR experiments. We follow the strategy that modifications of particle distributions at the freeze-out surface in the QCD phase diagram may be mapped directly to the observable ones within a sudden freeze-out scheme. We report first results of these investigations for the production of light clusters (deuterons and tritons) which can be compared to experimental data from the HADES and the NA49 experiment and for the interpretation of the "horn" effect observed in the collision energy dependence of the $K^+/π^+$ ratio. Medium effects on light cluster production in the QCD phase diagram are negligible at the highest NICA energies but shall play a dominant role at the lowest energies. A sharp "horn"-type signal in the $K^+/π^+$ ratio can be obtained when the onset of Bose condensation modelled by a pion chemical potential results in an enhancement of pions at low momenta (which is seen at LHC energies) and would occur already in the NICA energy range.
