Critical net-baryon fluctuations in an expanding system
Critical net-baryon fluctuations in an expanding system
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DOI：
10.1103/physrevc.107.014908
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发表时间：
2022-05
影响因子：
3.1
通讯作者：
Gr'egoire Pihan;M. Bluhm;M. Kitazawa;T. Sami;M. Nahrgang
中科院分区：
文献类型：
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作者：
Gr'egoire Pihan;M. Bluhm;M. Kitazawa;T. Sami;M. Nahrgang
在这项工作中，我们研究的后果，纵向Bjorken膨胀和哈勃一样的温度冷却方案上的1+ 1维非线性模型的净重子密度的微扰动力学。与格点QCD计算一致的是，在临界点的假定位置附近和零重化学势处，涨落的平衡行为完全编码在交叉侧的磁化率的温度依赖性中.我们证明了极大的灵敏度的波动观测的动力学，特别是对离散长度和冻结的条件。虽然临界信号是可见的并且临界区域通过扩展而加宽，但是过小的扩散长度可以强烈地减小信号的幅度。我们建议在实验上寻找重子在中等快度下的显著反关联，并绘制出四阶累积量的快度依赖性，在临界点的存在下（并且只有在临界点的存在下），四阶累积量在中等快度下具有明显的最小值。
In this work we study the consequences of a longitudinal Bjorken expansion and a Hubble-like temperature cooling scenario on a 1+1D non-linear model of the diffusive dynamics of fluctuations in the net-baryon density. The equilibrium behavior of the fluctuations is fully encoded in the temperature dependence of the susceptibilities on the crossover side both in the vicinity of the assumed location of the critical point and at vanishing baryo-chemical potential in-line with lattice QCD calculations. We demonstrate the great sensitivity of the fluctuation observables on the dynamics, in particular on the diffusion length and the freeze-out conditions. While the critical signals are visible and the critical region is broadened by the expansion, a too small diffusion length can strongly reduce the amplitude of the signals. We propose to search for significant anti-correlations of baryons at intermediate rapidity experimentally and to map out the rapidity dependence of the fourth-order cumulant, which in the presence of a critical point (and only in its presence) has a pronounced minimum at intermediate rapidities.