论文标题
利用高$ p_ \ perp $理论和数据来限制夸克 - 格鲁隆等离子体的初始阶段
Utilizing high-$p_\perp$ theory and data to constrain the initial stages of quark-gluon plasma
论文作者
论文摘要
在热化之前，夸克 - 杜伦等离子体的初始阶段的稀缺知识主要是通过低$ p_ \ perp $ sector推断出来的。我们在本报告中提出了一种补充方法 - 使用高$ P_ \ PERP $探针的能源损失。我们研究了四个通常假定的初始阶段的效果，其温度曲线仅在热化之前，对高$ p_ \ perp $ $ $ $ r_ {aa} $和$ v_2 $预测的影响。这些预测基于我们的动态辐射和弹性损失方法（DREENA）框架。我们将$ V_2 $的不敏感性报告到初始阶段，从而无法区分不同的情况。 $ r_ {aa} $显示对假定初始阶段的敏感性，但是当前的实验精度不允许在这些情况下解决。我们进一步修改了将每个单个初始阶段拟合能量损失参数的普遍接受的步骤，即所测量的$ r_ {aa} $。我们表明，$ v_2 $对通过此过程获得的各种初始阶段的敏感性主要是拟合过程的结果，这可能会掩盖物理解释。总体而言，对高$ p_ \ perp $可观察的同时研究，具有不变的能量损失参数化和限制温度剖面，对于初始阶段的将来限制至关重要。
The scarce knowledge of the initial stages of quark-gluon plasma before the thermalization is mostly inferred through the low-$p_\perp$ sector. We propose a complementary approach in this report - the use of high-$p_\perp$ probes' energy loss. We study the effects of four commonly assumed initial stages, whose temperature profiles differ only before the thermalization, on high-$p_\perp$ $R_{AA}$ and $v_2$ predictions. The predictions are based on our Dynamical Radiative and Elastic ENergy-loss Approach (DREENA) framework. We report insensitivity of $v_2$ to the initial stages, making it unable to distinguish between different cases. $R_{AA}$ displays sensitivity to the presumed initial stages, but current experimental precision does not allow resolution between these cases. We further revise the commonly accepted procedure of fitting the energy loss parameters, for each individual initial stage, to the measured $R_{AA}$. We show that the sensitivity of $v_2$ to various initial stages obtained through such procedure is mostly a consequence of fitting procedure, which may obscure the physical interpretations. Overall, the simultaneous study of high-$p_\perp$ observables, with unchanged energy loss parametrization and restrained temperature profiles, is crucial for future constraints on initial stages.
