论文标题
相对论重型离子碰撞中向量介子的局部自旋对齐
Local spin alignment of vector mesons in relativistic heavy-ion collisions
论文作者
论文摘要
我们研究了由重型离子碰撞中局部极化夸克和反夸克（局部自旋比对）引起的载体介子的自旋比对。我们发现$ρ_{00} \ neq 1/3 $不一定会向系统的轨道角动量列出夸克和反夸克的全局极化，但也可能源自它们的局部自旋极化。这种局部自旋极化可以是由于火球的各向异性扩张引起的局部涡度。我们进一步提出了可以区分局部和全局自旋比对的实验性可观察物。重型离子碰撞中这些可观察到的测量可以探测涡度模式，并在$ ϕ $和$ k^{*0} $旋转对齐的难题上发光。
We investigate the spin alignment of vector mesons arising from locally polarized quarks and anti-quarks (local spin alignment) in heavy-ion collisions. We find that $ρ_{00}\neq 1/3$ does not necessarily signal the global polarization of quarks and anti-quarks along the orbital angular momentum of the system, but may also originate from their local spin polarization. Such local spin polarization could be induced by local vorticity arising from the anisotropic expansion of the fireball. We further propose experimental observables that can distinguish between the local and the global spin alignments. Measurements of these observables in heavy-ion collisions can probe the vorticity pattern and shed light on the puzzles of $ϕ$ and $K^{*0}$ spin alignments.
