标题： 夸克-胶子等离子体中重夸克的反常输运行为 显示英文标题

标题： The errant life of a heavy quark in the quark-gluon plasma

摘要： 在QCD的高温相中，重夸克动量扩散常数通过涨落耗散关系决定了重夸克动力学平衡的速度。 这个输运系数可以通过 Kubo 公式从热关联函数中提取。 我们基于重夸克有效场论（HQET）最近对该问题的表述，给出了胶质等离子体中相关欧几里得关联函数的格点计算结果。 我们发现，当温度从$6T_c$降低到$2T_c$时，在最大时间分离处的欧几里得关联函数增强了$\approx20%$，这表明在较低温度下相互作用更强。 同时，关联函数从$6T_c$降到$2T_c$时变得平坦，显示出谱权重相对向低频段移动。 关联函数的一个近期的次领头阶微扰计算结果与格点数据的时间依赖性在百分之几的水平上一致。 我们估计了需要从微扰谱函数的$\omega\lesssim T$区域额外贡献多少，才能使它与$3.1T_c$处的格点数据一致。 显示英文摘要

摘要： In the high-temperature phase of QCD, the heavy quark momentum diffusion constant determines, via a fluctuation-dissipation relation, how fast a heavy quark kinetically equilibrates. This transport coefficient can be extracted from thermal correlators via a Kubo formula. We present a lattice calculation of the relevant Euclidean correlators in the gluon plasma, based on a recent formulation of the problem in heavy-quark effective field theory (HQET). We find a $\approx20%$ enhancement of the Euclidean correlator at maximal time separation as the temperature is lowered from $6T_c$ to $2T_c$, pointing to stronger interactions at lower temperatures. At the same time, the correlator becomes flatter from $6T_c$ down to $2T_c$, indicating a relative shift of the spectral weight to lower frequencies. A recent next-to-leading order perturbative calculation of the correlator agrees with the time dependence of the lattice data at the few-percent level. We estimate how much additional contribution from the $\omega\lesssim T$ region of the perturbative spectral function would be required to bring it in agreement with the lattice data at $3.1T_c$.