AI 中文总结
研究金-金碰撞中电荷K介子与K*0共振子定向流差异，揭示中心性依赖性及早期集体效应。
AI 中文摘要
我们给出了在\(\sqrt{s_{\mathrm{NN}}}\)=14.6、19.6和27 GeV的金金碰撞中，带电K介子、\(\phi\)介子和\(K^{*0}(\overline{K^{*0}})\)共振的快度奇数定向流（\(v_{1}^{\mathrm{odd}}\)）的测量结果。本研究首次测量了重离子碰撞中\(K^{*0}\)共振的\(v_{1}^{\mathrm{odd}}\)。我们的测量显示，带电K介子与\(K^{*0}\)共振之间的定向流存在中心度相关差异，且随着碰撞中心度增加而更显著。相比之下，带电K介子与\(\phi\)介子之间的定向流差异几乎与中心度无关。虽然各向异性流被认为在碰撞早期形成，但对于经历大量强子再散射的短寿命共振，如\(K^{*}(892)\)，尚不清楚观测到的\(v_{1}^{\mathrm{odd}}\)在多大程度上反映早期真正的部分子集体性，以及在多大程度上被后期强子相互作用和/或重建效应改变。当前测量对于厘清这些贡献并解决此问题至关重要。基于UrQMD模型包含强子后燃烧器的现有流体动力学计算表明，为了重现带电K介子与\(K^{*0}\)的\(v_{1}^{\mathrm{odd}}\)之间观测到的差异，需要由于再散射导致\(K^{*0}\)产额相对于一阶事件平面的不对称修正。
英文摘要
We present the measurement of rapidity-odd directed flow ($v_{1}^{\mathrm{odd}}$) for charged kaons, $ϕ$ mesons, and $K^{*0}(\overline{K^{*0}})$ resonances in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 14.6, 19.6 and 27 GeV. This study includes the first measurement of the $K^{*0}$ resonance $v_{1}^{\mathrm{odd}}$ in heavy-ion collisions. Our measurement shows a centrality-dependent difference in directed flow between charged kaons and $K^{*0}$ resonances, which becomes more pronounced with increasing collision centrality. In contrast, the difference in directed flow between charged kaons and $ϕ$ mesons remains nearly independent of centrality. Although anisotropic flow is thought to be developed in the early stages of the collision, for short-lived resonances such as the $K^{*}(892)$ that experience substantial hadronic re-scattering, it remains unclear to what extent the observed $v_{1}^{\mathrm{odd}}$ reflects genuine partonic collectivity in the early stage, and to what extent it is altered by late-stage hadronic interactions and/or reconstruction effects. The present measurement is crucial for disentangling these contributions and addressing this question. Existing hydrodynamic calculations that include a hadronic afterburner based on the UrQMD model indicate that an asymmetric modification of the $K^{*0}$ yield, due to rescattering, relative to the first-order event plane is required to reproduce the observed difference between $v_{1}^{\mathrm{odd}}$ for charged kaons and $K^{*0}$.
Comments7 pages, 5 figures
