高能重离子碰撞中喷注尾迹的椭圆风
The elliptic wind on jet wakes in high-energy heavy-ion collisions
AI总结：
本研究针对高能重离子碰撞中QGP的非均匀性，提出用γ-喷注事件中喷注-强子关联的平面内外差异，作为度量喷注尾迹椭圆展宽与加深的可观测量，可约束QGP的剪切粘度。
AI中文摘要：
在高能重离子碰撞中，快部分子传播于热夸克胶子等离子体（QGP）内时的能量损失会诱导出类马赫锥的介质响应。由于热QGP是不均匀的，其初始密度梯度也会产生集体流，因此该动态系统中喷注诱导的介质响应应同时受到集体流和密度梯度的扭曲。研究表明，这种扭曲会导致喷注尾迹展宽，且在非中心重离子碰撞中，由于密度梯度和流速度的椭圆各向异性，尾迹的横向宽度会随喷注传播的方位角变化。我们提出并计算了γ-喷注事件中软带电强子的喷注-强子关联的平面内与平面外差异，将其作为尾迹前沿的椭圆展宽和扩散尾迹加深的度量；同时研究了该可观测量对QGP介质剪切粘度的敏感性。RHIC和LHC上对椭圆流风导致的喷注尾迹方位角调制的实验测量，可进一步约束QGP介质的输运性质。
英文摘要：
Energy loss by fast partons induces a Mach-cone-like medium response as they propagate inside the hot quark-gluon plasma (QGP) in high-energy heavy-ion collisions. Because the QGP is nonuniform and its initial gradients generate collective flow, jet-induced medium response in this evolving system is also distorted by the flow and density gradient. This distortion leads to a broadened jet wake whose transverse width depends on the azimuthal angle of the jet propagation due to the elliptic anisotropy of the density gradient and the flow velocity in noncentral heavy-ion collisions. We propose and calculate the difference between the azimuth-dependent jet-hadron correlations for soft charged hadrons in in-plane and out-plane $γ$-jets as a measure of the elliptic broadening of the wake front and the deepening of the diffusion wake. We also study the sensitivity of this observable to the shear viscosity of the QGP. Experimental measurements of the azimuthal modulation of jet wakes induced by the wind of the elliptic flow at RHIC and LHC can provide additional constraints on the transport properties of the QGP.
