强子化是强相互作用理论的基本问题，也是相对论重离子碰撞中夸克胶子等离子体(QGP)与末态观测量联系的关键。RHIC 物理研究表明：夸克组合是QGP 强子化的必要机制。最近，STAR的能量扫描实验和SPS实验在碰撞质心能量5-20GeV的能区上发现了强子产生的新特征，如强子椭圆流的组分夸克数标度性破缺。此能区夸克组合是否仍然适用? QGP新物质态是否产生？本项目将利用山东夸克组合模型对碰撞能量5-200GeV的重离子碰撞中热强子尤其是奇异强子和共振态的产生规律进行系统研究。通过对集体流、重子-反重子关联、重子-奇异数关联等关联量、强子的产额和产额比的事件涨落以及强子重散射对强子产生特别是共振态产生的影响的研究，检验夸克组合机制的普适性，深入理解强子化规律，探索较低能区QGP的产生阈以及相变特征。

Hadronization is an important issue in non-purtubativie quantum chromodynamics (QCD). In relativistic heavy ion collisions, it is a key bridge between final-state observables and the quark gluon plasma (QGP) produced in early stage of collisions. RHIC physics show that the quark combination mechanism plays an indispensable role in the hadronization of QGP. Recently the Beam Energy Scan program of STAR Collaboration and SPS experiments at CERN found many new features of hadron production in heavy ion collisions in the low BES energy range 5-20GeV, e.g. the rule of quark number scaling for hadronic elliptic flow v2 is broken partially as the collision energy decreases to 11.5 GeV. Is the quark combination mechanism applicable in this energy region? Is QGP created? In this project, we will apply a quark combination model developed by Shandong Group to systematically study the production of various thermal hadrons, in particular, that of the strange hadrons and resonances in heavy ion collisions in the entire BES energy range(5-200 GeV). We shall investigate collective flows, baryon-antibaryon and baryon-strangeness correlation, event-by-event fluctuation of hadronic yields and yield ratios between different species of hadrons, effects of hadronic rescattering on hadron production, in particular on resonance production, to test the universality of quark combination mechanism and explore the creation threshold of QGP and the feature of phase transition at lower collisional energies.