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 QCD
--QCD and its applications to 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 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?
• 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
Quark Model of Hadrons
Baryon’s Quark Structure
2.Bases of Nuclear QCD
(1)QCD Lagrangian
BRST Symmetry of QCD Lagrangian
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
PQCD, Feynman Diagram
Basic Properties of QCD
Effective quark freedom
3. Nucleon and Nuclei
at High-Energy Scale
* Theory bases and approaches
QCD asymptotic freedom
QCD perturbation theory
Parton distributions, GPD, form factors
• Experiment measures:
Deep in-elastic scattering (DIS)
Processes
(1) Lepton-nucleon DIS and parton model
Quark parton distributions(1)
Quark parton distributions(2)
Quark parton distribution(3)
• Transversity distribution and tensor charge
(2) Parton model sum rules
Parton sum rules and quark-gluon
distributions in nucleon
• Spin-independent parton sum rules
Adler sum rule, Gross-Llewellyn sum rule,
Gottfried sum rule(GRS), Momentum sum rule
• Spin-dependent parton sum rules
Bjorken sum rule, GDH sum rule,
Generalized GDH sum rule,
Quark transversity sum rule and tensor charge
Bjorken sum rule
(3) Nucleon structure fromQCD
*Spin structure of nucleon
Perturbative Evolutions of QCD
angular momentum operators
Perturbative Evolutions of QCD
angular momentum operators
Perturbative Evolutions of QCD
angular momentum operators
In asymptotic limit, the quark spin contribution
is less then 0.36 for 3-flavor case
Quark spin contribution
to nucleon spin
Quark spin contribution
to nucleon spin
The measurement results are given at Q^2 =5 Gev^2
Effective theory analyses
QCD at low-energy is equivalent to an effective quark theory
Dynamically generated quark mass
Axial charges of the proton and
quark spin contribution to proton spin
The current quark spin contribution is
Which is exactly agreement with
HERMES’s result.
Tensor Charge of the Nucleon
• QCD perturbative evolitions
Note that gluons do not enter the evolution equation for
transversity distributions due to the chiral-odd property.
The evolution equation of tensor charge at leading order
Theory estimates of tensor charges
—model calculation results
Effective theory analyses
of tensor charges
• Flavor singlet tensor charge of current quark
contributions (in the asymptotic limit)
Flavor singlet axial charge
Flavor singlet tensor charge
Isovector tensor charge
Where m is dynamic mass of quark in the chiral limit
Scale dependence
of tensor & axial charges
Flavor singlet tensor charge(green line) and axial
charge(red line) with scale change
* Origin of nucleon mass
* Origin
of nucleon mass
*Nucleon
form factor
Form Factors of the Nucleon
•
•
•
•
Perrturbative QCD analysis
Lattice QCD calculations
Parametrization model of GPD
Light-cone sum rules
Parametrization model of GPD
(4) High-energy nucleon-nucleon
collision: Drell-Yan processes
(5) Lepton-nuclei DIS:
EMC effect
4. Nonperturbative QCD
*Study aim
* Quark and gluon color confinement
* Dynamically chiral symmetry breaking
* How to form nucleon(hadrons)
* Hadron states
* N-N interactions and nuclei
*Study approaches
•QCD Nonperturbative Approachs
•(a) Lattice
QCD (1)
•Lattice QCD (2)
•(b) Dyson-Schwiner Equations (1)
•Dyson-Schwinger Equations(2)
•Dyson-Schwinger Equations(3)
(c) QCD Sum Rules (1)
•QCD Sum Rules (2)
(d)
Effective Field Theory (1)
•Effective Field Theory (2)
•Effective Field Theory (3)
•Effective Field Theory (4)
•Effective Field Theory (5)
•Effective Field Theory (6)
(1)Quark-gluon confinement studies
*Confinement potential from lattice QCD
Linear confinement potential
from lattice QCD
Color-confinement mechanism
• QCD vacuum properties and color
confinement
--Magnetic monopoles and dual
superconductivity
• QCD nonperturbative interactions lead to
color confinement (confinement dynamics)
--Infrared slavery cased by the infrared
divergences of QCD green’s functions
*Color-confinement dynamics
• Color confinement scenarios
--- Infrared behaviors of gluon and ghost
propagators
• Dyson-Schwinger equations
• Lattice QCD calculations
• Quark-gluon vertex structure and quark
color confinement
Infrared behaviour of gluon and ghost
propagators in Yang-Mills theory
QCD quark-gluon vertex structure
H.X.He, Phys.Rev.D80, 016004 (2009)
(2) Low-energy effective models
--Bridge
•
•
•
•
•
between QCD and phenomena
GCM model
Chiral soliton model
NJL model
Quark-meson coupling model
Quark potential model(constitute quark
model)
5. Nucleon, N-N interactions &
Nuclei at Low-energy Scale
(1) From QCD to constitute quark model(CQM)
(2) The static properties of nucleon in CQM
* nucleon mass
* axial charge, tensor charge
* nucleon magnetics
* spin structure
* strange contents of nucleon
(3)Non-conventional (exotic)
hadron states
Glueballs
* Tetraquark states
* Quark-gluon hybrid states
* Pentaquark states
* Hexaquark states
* Nucleon-anti-nucleon bound states
*
(4) Nucleon-nucleon interactions
in quark model
Nucleon-Nucleon Interaction
in Quark Model
(5) Quark-meson coupling(QMC) model
and nuclear many-body problems(a)
Quark-meson coupling(QMC) model
and nuclear many-body problems(b)
Quark-meson coupling(QMC) model
and nuclear many-body problems
• QMC and QHD
• QMC and Skyrme effective nuclear force
• Saturation property and incompressibility
of nuclear matter
• Modefications of mass and properties of hadron
• Finite nuclei in QMC model
• The quark structure effects of nucleon in nuclear
matter
*Saturation property and incompressibility
of nuclear matter
Modefications of nucleon mass in
nuclear matter(a)
*Modefications of nucleon mass in
nuclear matter(b)
* QMC and Skyrme effective nuclear force(a)
•QMC and Skyrme effective nuclear force(b)
•Finite nuclei in QMC model(a)
•Finite nuclei in QMC model(b)
* Finite nuclei in QMC model(c)
Summary
QCD (quarks, gluons)
Nucleons, mesons,…
Nucleon-nucleon interactions
Nuclear matter, nuclei