核色动力学导论 用量子色动力学描绘 现代核物理的蓝图 何汉新 中国原子能科学研究院
核色动力学导论 ---用量子色动力学描绘 现代核物理的蓝图 何汉新 中国原子能科学研究院
An Introduction to Nuclear OCD QCD and its applications to the systems of nucleon and nuclear structure He. ha an-xIn China Institute of Atomic Energy
An Introduction to Nuclear QCD --QCD and its applicationsto the systems of nucleon and nuclear structure He, Han-xin China Institute of Atomic Energy
Contents 1. What is nuclear QCD? Why apply QCD to nucleonic and nuclear systems? 2. Bases of nuclear OCD QCD and its properties 3. Nucleon and nuclei at high-energy scale 4. Nonperturbative QCD studies 5. Nucleon, nuclei at low-energy scale 6. Summery
Contents 1. What is nuclear QCD? Why apply QCD to nucleonic and nuclear systems? 2. Bases of nuclear QCD: QCD and its properties 3. Nucleon and nuclei at high-energy scale 4. Nonperturbative QCD studies 5. Nucleon, nuclei at low-energy scale 6. Summery
1. What is nuclear QCD? *Why apply qcd to nucleonic and nuclear systems raditional nuclear physIcs nuclei are composed of point-like nucleons Dynamics: Quantum mechanics DIS experiments: nucleon has structure Quark model Proton: uud Nutron: ddu Strong interaction dynamics: QCD Nuclear chromodynamics
1. What is nuclear QCD? *Why apply QCD to nucleonic and nuclear systems? • Traditional nuclear physics: nuclei are composed of point-like nucleons Dynamics: Quantum mechanics • DIS experiments: nucleon has structure • Quark model: Proton: uud Nutron: ddu • Strong interaction dynamics: QCD • Nuclear chromodynamics
Quark model of hadrons 夸克模型假设强子是复合粒子,构成强子的基本砖块称为夸克.夸克是 自旋为1/2、重子数为1/3、带有分数电荷的费米子,它还具有“味”、“色”的 量子数.已知的六种“味”的夸克为:上(u)、下(d)粲(c)、奇(s)、顶(t)、底 (b).量子数“色”是由夸克服从狄拉克-费米自旋统计原理(见表1.1)要 表11夸克与它们的量子数 味(质量电荷同位旋/3奇异数S粲数C底数B顶数T u0.002-000823 d0.0060.015-1/3 1→-1.6 23 000 0.1→0.3 1/3 00000 ~174 2/3 0000 001000 000010 b41→45 1/3
Quark Model of Hadrons
Quark Model of hadrons 根据色禁闭假设和泡利原理,我们就可用夸克作为基本砖块来构造各 种可能的强子2,让我们考虑核物理感兴趣的u、d、S夸克组成的强子,并暂 不计它们的质量差,则SU(3)f是好的对称性.夸克属于SU(3)r的基本 表示 3 反夸克为表示3.介子由夸克和反夸克组成,而重子由3个夸克组成,因此介 子(可q)和重子(q)按下述张量乘积分解 33-8∞1 (1.2) 3③383=38(683)=1088881 分类,由此介子包含八重态和单态,重子则显示出有十重态、八重态和单态
Quark Model of Hadrons
Baryons Quark structure 重子的夸克结构有如下形式: 2 uud. n= ddu ∑+=Ws,∑=s(ud+du),S-=dds 三=Wss,=ds,A"=±(dw-wds
Baryon’s Quark Structure
2. Bases of Nuclear QCD (QCD Lagrangian 量子色动力学(CD— Quantum Chromodynamics)是色空间的 SU(3)C非阿贝尔规范理论3,,这里,带色荷的费米子是夸克,设其场量为 y,其中f=ud,s…为“味”指标,a=1,2,3为“色”指标,带色的规范玻色 子称为“胶子”,设其场是为Ag,a=1,2…,8,为胶子的色指标g为Dira 指标,满足定域规范不变性的经典的色动力学拉氏密度为; OCD (1.32) 其中 Fa=au Aa+ faba As D,=a, - u
2.Bases of Nuclear QCD (1)QCD Lagrangian
BRST Symmetry of QCD Lagrangian 无穷小BRST变换; ψ=-1g⑦ca δψ=igC Cb δca=+- gfabccbc oc (,4)
BRST Symmetry of QCD Lagrangian
QCD Symmetries, Conservation Laws and dentities *BRST symmetry and Ward-Takahashi(slavnov-Taylor ) identities Labor symmetries and conservation laws "QCD energy-momentum tensor PQCD angular momentum tensor
QCD Symmetries, Conservation Laws and Identities • *BRST symmetry and Ward-Takahashi(Slavnov-Taylor) identities • *Glabor symmetries and conservation laws • *QCD energy-momentum tensor • *QCD angular momentum tensor
