论文标题
使用Pythia Angantyr和IreQMD对重离子碰撞的研究
Studies of heavy-ion collisions using PYTHIA Angantyr and UrQMD
论文作者
论文摘要
在本文中，我们从新的无QGP，无平衡的，改进了重型离子碰撞的基线模型中进行了预测。它由pythia angantyr事件发生器组成，耦合到ureqmd，作为HADRONIC CASCADE SIMULATOR，并将其与$ \ sqrt {s _ {\ rm {nn}}}} $ = 2.76 $ = 2.76 $ = 2.76 $ = 2.76 tev进行了比较。由于HADRON顶点模型在Pythia Angantyr中的新实现，因此可以实现这种耦合。在口气中进行的习惯逆转被证明会导致对中部至高$ p_ \ perp $粒子产量的显着抑制，这与核修饰因子的测量在质量上是一致的。我们进一步研究了通过使用两粒子相关性，即使没有任何党的能量损失，也出现了两粒子相关性，并表明某种抑制客场的抑制也会发生在HADRONES相中，并且表明某种抑制是在HADRONE阶段发生的。最后，高电平动量的Dijet结构的去相关也导致椭圆流系数$ v_ {2} \ {2 \} $的减少。这些发现表明，明显的类似喷气液样的效应仍然可能起源于习惯性，而不是党派阶段，并证明通常由不一致的PP碰撞叠加组成的通常的PB-PB基线，忽略了与QGP并不严格相关的相干现象，但仍可能是高度相关的。
In this paper, we show predictions from a new QGP-free, no-equilibration, improved baseline model for heavy-ion collisions. It is comprised of the PYTHIA Angantyr event generator coupled to UrQMD, as a hadronic cascade simulator, and compared to ALICE and CMS data from Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 2.76 TeV. This coupling is made possible due to a new implementation of the hadron vertex model in PYTHIA Angantyr. Hadronic rescattering in UrQMD is shown to lead to a significant suppression of mid- to high-$p_\perp$ particle yields that is qualitatively consistent with measurements of nuclear modification factors. We further study the effect of hadronic rescatterings on high-$p_\perp$ particles by using two-particle correlations and show that some suppression of away-side jets occurs in the hadronic phase even without any partonic energy loss. Finally, the decorrelation of dijet structures at high momenta also leads to a reduction of the elliptic flow coefficient $v_{2}\{2\}$. These findings suggest that significant jet-quenching-like effects may still originate in the hadronic, as opposed to the partonic phase and prove that the usual Pb-Pb baseline, composed of a superposition of incoherent pp collisions, ignores coherent phenomena that are not strictly related to the QGP but may still be highly relevant.
