超出非相对论极限的夸克胶子等离子体中重夸克输运
Heavy quark transport in quark-gluon plasma beyond the non-relativistic limit
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中文总结 AI 辅助
该研究针对QCD中重夸克输运的非高斯特性，提出不依赖耦合强度假设的新描述方法，以$\boldsymbol{\textit{N}=4}$ SYM为例演示重夸克热化，为提取QGP新信息铺路。
中文摘要 AI 辅助
重离子碰撞中形成的夸克胶子等离子体（QGP）中重夸克的动力学为表征其性质提供了独特窗口。现有描述介质中重夸克的方法要么依赖QGP的准粒子模型，要么假设介质的动量转移遵循高斯统计，但这两种假设在量子色动力学（QCD）中都不能想当然成立。实际上，在强耦合的原型理论$\boldsymbol{\textit{N}=4}$超对称杨-米尔斯理论（$\boldsymbol{\textit{N}=4}$ SYM）中，早已不存在携带动量的准粒子；此外，我们近期研究表明，介质的动量转移远非高斯分布[arXiv:2501.06289]。此后，我们进一步证实，该动量转移在能量损失与能量增益之间的不对称性（不仅影响分布的高斯特性，还会影响其所有矩）实际上具有普适性[arXiv:2504.21139]。因此，为了以符合量子场论（QFT）原理的方式将初始重夸克产生截面与最终强子谱关联起来，需要新方法。本文中，我们提出一种新的重夸克输运描述，其编码了介质动量转移的所有非高斯特性，所有这些特性均可在QCD中定义且原则上可计算，无需依赖耦合强度的任何假设。作为演示示例，我们讨论了$\boldsymbol{\textit{N}=4}$ SYM中的重夸克热化，这为提取QGP基本性质的新信息铺平了道路。
英文摘要
The dynamics of heavy quarks in quark-gluon plasma (QGP) formed in heavy ion collisions provide a unique window to characterize its properties. Existing approaches to describe heavy quarks in medium rely either on quasiparticle-based models of QGP, or on assuming that the momentum transfer from the medium follows Gaussian statistics. However, neither of these assumptions can be taken for granted in QCD. In fact, in the prototypical theory that is strongly coupled $\mathcal{N}=4$ SYM, it has been long known there are no momentum-carrying quasiparticles, and furthermore, we have recently shown that the momentum transfer from the medium is far from being Gaussian [arXiv:2501.06289]. Since then, we showed that the asymmetry of said momentum transfer between energy loss and energy gain -- which affects all moments of the distribution, not only its Gaussian characteristics -- is, in fact, universal [arXiv:2504.21139]. Therefore, in order to connect the initial heavy quark production cross section with the final hadron spectrum in a way that is consistent with QFT principles, new methods are needed. In this talk, we present a new transport description of heavy quarks that encodes all of the non-Gaussian features of the momentum transfer from the medium, all of which can be defined and in principle calculated in QCD, without relying on any assumptions regarding the strength of the coupling. As a demonstrative example, we discuss heavy quark equilibration in $\mathcal{N}=4$ SYM. This paves the way towards extracting novel information about fundamental properties of QGP.
