Institute of Physics Belgrade, University of Belgrade, Pregrevica 118, 11080 Belgrade, Serbia.
Phys Rev Lett. 2014 Jan 31;112(4):042302. doi: 10.1103/PhysRevLett.112.042302.
Both charged hadrons and D mesons are considered to be excellent probes of QCD matter created in ultrarelativistic heavy ion collisions. Surprisingly, recent experimental observations at LHC show the same jet suppression for these two probes, which--contrary to pQCD expectations--may suggest similar energy losses for light quarks and gluons in the QCD medium. We here use our recently developed energy loss formalism in a finite-size dynamical QCD medium to analyze this phenomenon that we denote as the "heavy flavor puzzle at LHC." We show that this puzzle is a consequence of an unusual combination of the suppression and fragmentation patterns and, in fact, does not require invoking the same energy loss for light partons. Furthermore, we show that this combination leads to a simple relationship between the suppressions of charged hadrons and D mesons and the corresponding bare quark suppressions. Consequently, a coincidental matching of jet suppression and fragmentation allows considerably simplifying the interpretation of the corresponding experimental data.
带电强子和 D 介子都被认为是研究在相对论重离子碰撞中产生的 QCD 物质的优秀探针。令人惊讶的是，最近 LHC 的实验观测表明，这两种探针的喷注抑制相同，这与 pQCD 的预期相反，可能表明在 QCD 介质中轻夸克和胶子的能量损失相似。我们在这里使用我们最近开发的在有限大小动力学 QCD 介质中的能量损失形式来分析这一现象，我们将其称为“LHC 上的重味难题”。我们表明，这个难题是抑制和碎裂模式的不寻常组合的结果，实际上并不需要为轻部分子调用相同的能量损失。此外，我们表明，这种组合导致带电强子和 D 介子的抑制与相应的裸夸克抑制之间存在简单关系。因此，喷注抑制和碎裂的巧合匹配使得解释相应的实验数据变得相当简单。
