论文标题
RHIC和LHC的D介子的定向流：非扰动动力学，纵向散装物质不对称和电磁场
Directed flow of D mesons at RHIC and LHC: non-perturbative dynamics, longitudinal bulk matter asymmetry and electromagnetic fields
论文作者
论文摘要
我们介绍了针对$ d $ Meson的定向流量$ v_1 $的研究，讨论了初始涡度和电磁场的影响。最近的研究预测，预计$ d $ ersons的$ v_1 $预计将比带电的光子hadrons大得多。我们澄清，这是由于一种不同的机制导致导致相对论和非偏见能量的批量物质之一的定向流动形成。我们指出，只有在散装物质和魅力夸克之间存在纵向不对称时，才能生成非常大的$ v_1 $，并且如果后者在QGP介质中具有很大的非扰动互动，则才能产生。如果扩散系数能够正确预测$ r_ {aa}（p_t）$，$ v_ {2}（p_t）$和$ v_ {3}（p_t）$ d $ d $ Meson的$。此外，建立$ v_1（y）$的机制与相当小的地层时间相关联，可以预期对魅力扩散系数的初始高温依赖性更为敏感。我们还讨论了$ d^0 $和$ \ bar d^0 $的$ v_1 $的分配，这再次远比观察到的电磁粒子大得多，并且与恒星的数据一致，但是，这些差异仍然与误差杆相当，而在LHC标准的电磁概况中，假设恒定的电导率是不稳定的，则无法实现恒定的电导率。
We present a study of the directed flow $v_1$ for $D$ mesons discussing both the impact of initial vorticity and electromagnetic field. Recent studies predicted that $v_1$ for $D$ mesons is expected to be surprisingly much larger than that of light charged hadrons; we clarify that this is due to a different mechanism leading to the formation of a directed flow with respect to the one of the bulk matter at both relativistic and non-relativistic energies. We point out that the very large $v_1$ for $D$ mesons can be generated only if there is a longitudinal asymmetry between the bulk matter and the charm quarks and if the latter have a large non-perturbative interaction in the QGP medium. A quite good agreement with the data of STAR and ALICE is obtained if the diffusion coefficient able to correctly predict the $R_{AA}(p_T)$, $v_{2}(p_T)$ and $v_{3}(p_T)$ of $D$ meson is employed. Furthermore, the mechanism for the build-up of the $v_1(y)$ is associated to a quite small formation time that can be expected to be more sensitive to the initial high-temperature dependence of the charm diffusion coefficient. We discuss also the splitting of $v_1$ for $D^0$ and $\bar D^0$ due to the electromagnetic field that is again much larger than the one observed for charged particles and in agreement with the data by STAR that have however still error bars comparable with the splitting itself, while at LHC standard electromagnetic profile assuming a constant conductivity is not able to account for the huge splitting observed.
