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arXiv 0901.2823hep-ph
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高能量子色动力学与统计物理

Quantum chromodynamics at high energy and statistical physics

S. Munier

摘要:

当强子在高能散射时,在相互作用点产生强色场,其动力学过程可用量子色动力学(QCD)描述。如果用部分子(夸克和胶子)来表示这些场,则后者的平均数密度在高能处饱和。在这一点上,非线性效应成为主导的动力学方程。在QCD的这个区域中得到的强子态一般被称为“彩色玻璃凝聚体”。我们对量子色动力学散射的理解得益于统计物理和数学物理的最新进展。在固定碰撞参量下,在非线性部分子饱和效应变得相当大的范围内,强子散射振幅的演化与经典粒子系统经历反应扩散过程的时间演化相似.这种系统的动力学本质上是由随机Fisher-Kolmogorov-Petrovsky-Piscounov方程的普适类中的方程控制的,该方程是随机非线性偏微分方程。这类方程的实现(即粒子物理学语言中的“事件”)具有嘈杂的行波形式。后者的普适性质可以用QCD中的散射振幅来表示。本文简要介绍了量子色动力学中统计物理的基本方法,总结了量子色动力学与统计物理的对应关系及其理论和唯象意义。

英文摘要:

When hadrons scatter at high energies, strong color fields, whose dynamics is described by quantum chromodynamics (QCD), are generated at the interaction point. If one represents these fields in terms of partons (quarks and gluons), the average number densities of the latter saturate at ultrahigh energies. At that point, nonlinear effects become predominant in the dynamical equations. The hadronic states that one gets in this regime of QCD are generically called ``color glass condensates''. Our understanding of scattering in QCD has benefited from recent progress in statistical and mathematical physics. The evolution of hadronic scattering amplitudes at fixed impact parameter in the regime where nonlinear parton saturation effects become sizable was shown to be similar to the time evolution of a system of classical particles undergoing reaction-diffusion processes. The dynamics of such a system is essentially governed by equations in the universality class of the stochastic Fisher-Kolmogorov-Petrovsky-Piscounov equation, which is a stochastic nonlinear partial differential equation. Realizations of that kind of equations (that is, ``events'' in a particle physics language) have the form of noisy traveling waves. Universal properties of the latter can be taken over to scattering amplitudes in QCD. This review provides an introduction to the basic methods of statistical physics useful in QCD, and summarizes the correspondence between these two fields and its theoretical and phenomenological implications.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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