核子自旋结构若干争议问题的研究

项目名称： 核子自旋结构若干争议问题的研究

项目编号： No.11275077

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 数理科学和化学

项目作者： 陈相松

作者单位： 华中科技大学

项目金额： 80万元

中文摘要： 为解决核子自旋结构中的规范相关难题，我们在[PRL100:232002]及[PRL103:062001]提出把规范场分解为物理部分和纯规范部分的方法，为构造规范不变的物理量提供了新的思路，引起了多位学者的继续研究,也引起了对核子自旋的规范不变分解方法乃至对规范对称性本身的很大争议。本项目将集中研究几个关键的争议点：1）规范场能否唯一地分解为物理部分和纯规范部分，这种分解是否具有实质性的物理意义；2）能否用实验检验人们提出的各种自旋与轨道角动量的表达式，特别是规范场的角动量表达式；3）能否从高能散射实验中抽取基于规范场物理分解方法而构造的新的夸克与胶子的规范不变分布函数，包括极化分布函数；4）是否存在"折中"的核子自旋规范不变分解，即我们曾经用路径积分方法尝试证明、著名学者Elliot Leader最近用正则量子化方法探讨的现象：规范有关的角动量算子在极化核子态上的期望值可能规范无关。

中文关键词： 能量-动量张量；角动量张量；量子测量；引力耦合理论；反常几何自旋霍尔效应

英文摘要： To solve the gauge-dependence difficulty in nucleon spin structure, we proposed in [PRL100:232002] and [PRL103:062001] the method of separating the gauge field into phyical and pure-gauge parts, which brought new idea for constructing gauge-invariant physical quantities, stimulated further research of many scholars, and also aroused intensive controvercy regarding the method of gauge-independent decomposition of the nucleon spin and even the gauge systry itself. This project will concentrate on the study of several key isses under debate: 1) whether or not can the gauge field be uniquely decomposed into a physical part plus a pure-gauge part, and whether such decomposition has essential physical meaning; 2) whether it is possible to experimentally test the proposed various expressions of spin and orbital angular momentum, especially the angular-momentum expression of the gauge field; 3) whether it is possible to extract from high-energy scattering experiments the new gauge-invariant quark and gluon distribution functions, including the polarized ones, based on the method of physical decomposition of the gauge field; 4) whether there exits a "compromising" gauge-invariant decomposition of the nucleon spin, namely the phenomenon which we had attemped to prove with the path-integral method and recently was explored

英文关键词： energy-momentum tensor；angular momentum tensor；quantum measurement；theory of gravitational coupling；anomalous geometric spin-Hall effect