Information AboutC-parity |
| CATEGORIES ABOUT C-SYMMETRY | |
| quantum field theory | |
| symmetry | |
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CHARGE REVERSAL IN ELECTROMAGNETISM The laws of and Magnetic Field s were reversed, the dynamics would preserve the same form. In the language of Quantum Field Theory , charge conjugation transforms: # # # Notice that these transformations do not alter the Chirality of particles. A left-handed Neutrino would be taken by charge conjugation into a left-handed Antineutrino , which does not interact in the Standard Model. This property is what is meant by the "maximal violation" of C-symmetry in the weak interaction. (Some postulated extensions of the Standard Model , like Left-right Model s, restore this C-symmetry.) COMBINATION OF CHARGE AND PARITY REVERSAL It was believed for some time that C-symmetry could be combined with the Parity -inversion transformation (see P-symmetry ) to preserve a combined CP-symmetry . However, violations of even this symmetry have now been identified in the weak interactions (particularly in the Kaon s and B Meson s). In the Standard Model, this CP Violation is due to a single phase in the CKM Matrix . If CP is combined with time reversal ( T-symmetry ), the resulting CPT-symmetry can be shown using only the Wightman Axioms to be universally obeyed. AMBIGUITY IN CHARGE DEFINITION There is really a lot of ambiguity and arbitrariness in the definition of charge conjugation. To give an example, take two real scalar fields, φ and χ. Formulated as it is, both fields have even C-parity. Now reformulate things so that . Now, φ has an even C-parity whereas χ has an odd C-parity. But let's redefine . Now it's the other way around. Similarly, a complex Weyl Spinor can be reexpressed as a real Majorana Spinor and vice versa. This arbitrariness allows physicists to define C the way it is in Left-right Model s. |
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