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fermion も加える. Lagrangian. Feynman rules. gluon. propagator. vertices. FP ghost. vertex. propagator. quark. vertex. propagator. Feynman rules. internal lines. propagators. gluon. quark. FP ghost. gluon. propagator. vertices. FP ghost. vertex. propagator. quark. vertex.
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fermionも加える Lagrangian
Feynman rules gluon propagator vertices FP ghost vertex propagator quark vertex propagator
Feynman rules internal lines propagators gluon quark FP ghost gluon propagator vertices FP ghost vertex propagator quark vertex propagator
Feynman rules internal lines propagators gluon quark FP ghost gluon propagator vertices FP ghost vertex propagator quark vertex propagator
Feynman rules internal lines propagators gluon quark FP ghost gluon = FP ghost quark
Feynman rules gluon vertices 3 gluon vertex 4 gluon vertex gluon propagator vertices FP ghost vertex propagator quark vertex propagator
Feynman rules gluon vertices 3 gluon vertex 4 gluon vertex 3 gluon vertex 4 gluon vertex
Feynman rules ghost-gluon vertex fermion-gluon vertex gluon propagator vertices FP ghost vertex propagator quark vertex propagator
Feynman rules ghost-gluon vertex fermion-gluon vertex ghost-gluon vertex fermion-gluon vertex
external lines gluon 1 FP ghost incoming outgoing quark anti-quark loop fermion loop -1 T matrix
loop diagrams dimension
+ finite terms + finite terms + finite terms
4 ghost gluon vertex part 収束 ghost ghost 2 gluon vertex part 収束 収束
relation among numbers = # of internal fermion lines, = # of internal boson lines = # of external boson lines = # of external fermion lines, = # of loops, = # of differentiations at vertices, divergent if depends only on the numbers of external lines
primitive divergences gluon self energy part quark self energy part ghost self energy part quark quark gluon vertex part ghost ghost gluon vertex part 4 gluon vertex part 3 gluon vertex part
renormalization r: renormalized quantity ZX: renormalization constant :renormalized Lagrangian, :counter term
renormalization There always exist counter terms for divergences. e.g. The divergences are polynomials in momentum. BPHZ renormalization (Bogoliubov Parasiuk Hep Zimmermann) The divergences can be absorbed by The gauge symmetry (or BRS symmetry) ensures the Slavnov Taylor identities and The divergences can be absorved by
at one loop level + finite terms
+ finite terms + + + finite terms
+ + + finite terms + finite terms
+ + + + + finite terms
Renormalization Condition In absorbing divergences by there remain ambiguities of finite constants. The condition to fix the ambiguities is called renormalization condition. The scheme with the renormalization condition is called renormalization scheme minimal subtraction scheme modified minimal subtraction scheme momentum subtraction scheme on-shell renormalization scheme Observable relations do not depend on the renormalization scheme