Variable Energy Cyclotron Centre, Kolkata, India.
Nuclear Physics Institute, Academy of Sciences of the Czech Republic, Řež u Prahy, Czech Republic.
Phys Rev Lett. 2018 Mar 9;120(10):102301. doi: 10.1103/PhysRevLett.120.102301.
The azimuthal anisotropy coefficient v_{2} of prompt D^{0}, D^{+}, D^{*+}, and D_{s}^{+} mesons was measured in midcentral (30%-50% centrality class) Pb-Pb collisions at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02 TeV, with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at midrapidity, |y|<0.8, in the transverse momentum interval 1<p_{T}<24 GeV/c. The measured D-meson v_{2} has similar values as that of charged pions. The D_{s}^{+} v_{2}, measured for the first time, is found to be compatible with that of nonstrange D mesons. The measurements are compared with theoretical calculations of charm-quark transport in a hydrodynamically expanding medium and have the potential to constrain medium parameters.
在质心能量对每核子对为 sqrt[s_{NN}]=5.02 TeV 的中 centrality (30%-50% centrality class) Pb-Pb 碰撞中,使用 LHC 上的 ALICE 探测器测量了 prompt D^{0}、D^{+}、D^{*+}和 D_{s}^{+}介子的各向异性系数 v_{2}。在横向动量间隔 1<p_{T}<24 GeV/c 内,通过它们在中间快度 |y|<0.8 的强子衰变,在 midrapidity 重建了 D 介子。测量的 D 介子 v_{2}与带电π介子的值相似。首次测量的 D_{s}^{+} v_{2} 被发现与非奇异 D 介子的值兼容。这些测量结果与在流体力学膨胀介质中 charm 夸克输运的理论计算进行了比较,有可能限制介质参数。