论文标题
在光线上的平均场夸克
Mean Field Quarks on the Light Front
论文作者
论文摘要
我们提出了一种基于X> 0.05时价夸克的频谱来计算核子中价夸克分布的新方法，该方法是通过三种主要机制生成的：价值夸克与残留核系统产生的平均场的相互作用，由两个和三个Quark Shart Short互动通过Gluon Exchands产生。在当前的报告中，我们介绍了项目的第一阶段，在该项目中，我们开发了一个非扰动模型，用于在核次内部平均值中的价夸克相互作用，以描述其在中度x区域中的分布（0.05 <x <0.4）。我们方法中的短范围夸克 - 夸克相互作用效果产生了价夸克分布的高X尾部。提出的非扰动模型基于以下图片，在该图的情况下，三个相对论价夸克在$ \ le 0.5 $ fm的距离处占据了核子核心，同时在残留核子系统产生的平均场中相互作用。该计算基于对这些夸克与残留系统的长距离相互作用的短距离价夸克的内部相互作用的A分解的假设。理论方法是基于有效的轻型图形方法，它使我们能够以一致的方式引入价夸克和残留系统波函数。这些波函数的参数通过xf_q（x）Q_0 QUARK QUARKS的峰位置固定在Q_0的Q_0 QF_Q（x）分布，Q_0与Charm-Quark质量相对应。几乎没有参数，我们可以在中等x区域（x <0.4）中对上下价值夸克分布进行了非常合理的描述，其中人们期望平均场动力学占主导地位。然而，该模型系统地低估了高$ x $区域，在这种区域中，预计党派短期相关性的贡献得到了增强。
We present a new approach for the calculation of the valence quark distributions in the nucleon based on the scenario in which the spectrum of the valence quarks at x>0.05 is generated through three main mechanisms: interaction of valence quarks with the mean field generated by the residual nucleon system, two and three quark short range interactions through gluon exchanges. In the current report we present the first phase of the project in which we develop a non-perturbative model for valence quark interaction in the mean field of the nucleonic interior to describe their distribution in the moderate x region (0.05 < x < 0.4). The short range quark-quark interaction effects in our approach generate the high x tail of valence quark distributions. The presented non-perturbative model is based on the picture in which three relativistic valence quarks occupy the nucleon core at distances of $\le 0.5$ Fm while interacting in the mean field generated by the residual nucleon system. The calculations are based on the assumption of the a factorization of the internal interaction of short-range three valence quarks with the long-range interaction of these quarks with the residual system. The theoretical approach is based on effective light-front diagrammatic approach which allows us to introduce the valence quark and residual system wave functions in a consistent way The parameters of these wave functions are fixed by the position of the peak of the xf_q(x) distribution of valence quarks at Q_0 corresponding to the charm-quark mass. With few parameters we achieved a very reasonable description of the up and down valence quark distributions in the moderate x region (x < 0.4), where one expects the mean field dynamics to dominate. The model, however, systematically underestimates the high $x$ region where enhanced contributions from partonic short-range correlations are expected.
