We study the hadron production in \(p+p\), \(p+n\) and \(n+n\) reactions within the microscopic Parton–Hadron-Dynamics (PHSD) transport approach in comparison to PYTHIA 8.2. We discuss the details of the “PHSD tune” of the Lund string model (realized by event generators FRITIOF and PYTHIA) in the vacuum (as in \(N+N\) collisions) as well as its in-medium modifications relevant for heavy-ion collisions where a hot and dense matter is produced. We compare the results of PHSD and PYTHIA 8.2 (default version) for the excitation function of hadron multiplicities as well as differential rapidity y, transverse momentum \(p_T\) and \(x_F\) distributions in \(p+p\), \(p+n\) and \(n+n\) reactions with the existing experimental data in the energy range \(\sqrt{s_{NN}} = 2.7 - 7000\) GeV. We discuss the production mechanisms of hadrons and the role of final state interactions (FSI) due to the hadronic rescattering. We also show the influence of the possible quark–gluon plasma (QGP) formation on hadronic observables in \(p+p\) collisions at LHC energies. We stress the importance of developing a reliable event generator for elementary reactions from low to ultra-relativistic energies in view of actual and upcoming heavy-ion experiments.

中文翻译：

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从低到超相对论能量的基本核子-核子反应中的强子产生

与PYTHIA 8.2相比，我们在微观Parton-Hadron-Dynamics（PHSD）传输方法中研究了\（p + p \），\（p + n \）和\（n + n \）反应中强子的产生。我们将在真空（如\（N + N \）碰撞）中讨论Lund字符串模型（由事件生成器FRITIOF和PYTHIA实现）的“ PHSD调”的详细信息，以及与重载有关的中等修改离子碰撞会在其中产生热的致密物质。我们比较了PHSD和PYTHIA 8.2（默认版本）的强子多重性激发函数以及微分速度y，横向动量\（p_T \）和\（x_F \）分布的结果。\（P + P \） ，\（P + N \）和\（N + N \）与所述能量范围现有的实验数据反应\（\ SQRT {S_ {NN}} = 2.7 - 7000 \）电子伏特。我们讨论了强子的产生机理以及由于强子散射而导致的最终状态相互作用（FSI）的作用。我们还显示了在LHC能量\（p + p \）碰撞中，可能的夸克-胶子等离子体（QGP）形成对强子可观测物的影响。考虑到实际和即将进行的重离子实验，我们强调开发一种可靠的事件生成器的重要性，该事件生成器适用于从低到超相对论能量的基本反应。