We study the production of pions, kaons, and (anti-) protons using A Multi Phase Transport (AMPT) Model in collisions at $\sNN=$ 7.7, 27, and 200 GeV. We present the centrality and energy dependence of various bulk observables such as invariant yields as a function of transverse momentum , particle yields $dN/dy$, average transverse momentum and various particle ratios, and compare them with experimental data. Both default and string melting (SM) versions of the AMPT model are used with three different sets of initial conditions. We observe that neither the default nor the SM version of the model could consistently describe the centrality dependence of all observables at the above energies with any one set of initial conditions. The energy dependence behavior of the experimental observables for 0–5% central collisions is in general better described by the default AMPT model using the modified HIJING parameters for Lund string fragmentation and 3 mb parton scattering cross-section. In addition, the kaon production as well as the $K/\pi$ ratio at 7.7 GeV is under-predicted by the AMPT model.

中文翻译：

---

使用多相输运模型在BNL相对论重离子对撞机可用的能量下限制Au + Au碰撞中的粒子生成机制

我们在$ \ sNN = $ 7.7、27和200 GeV的碰撞中使用多相传输（AMPT）模型研究了离子，钾和（反）质子的产生。我们介绍了各种体积可观观测值的中心性和能量依赖性，例如不变产量与横向动量，颗粒产量的函数关系。$dñ/dÿ$，平均横向动量和各种粒子比率，并将其与实验数据进行比较。AMPT模型的默认版本和字符串熔化（SM）版本都与三组不同的初始条件一起使用。我们观察到，模型的默认版本和SM版本都不能始终如一地描述在任意一组初始条件下上述能量下所有可观测物的中心性依赖性。对于默认的AMPT模型，使用修改后的HIJING参数（针对隆德弦碎裂和3 mb的部分散射截面）的默认AMPT模型可以更好地描述实验观察到的0-5％中心碰撞的能量依赖性行为。此外，kaon生产以及$ķ/\pi$ AMPT模型低估了7.7 GeV的比率。