Gauge theories of microweak CP violation
Abstract
We investigate systematically the condition that CP violation in |ΔS|=1 processes is "microweak" [i.e., of order of GFɛ(mmW)2 where m is a typical hadronic mass] naturally (i.e., for all values of complex parameters of the theory) in SU(2) × U(1) gauge theories of weak and electromagnetic interactions. We consider only those models in which CP violation occurs in the quark mass terms. The conditions for microweak CP violation in |ΔS|=1 processes are that (1) quarks of charge -13 and of a given chirality have the same weak isospin I and I3, and (2) quarks of charge 23 (-43, if they exist) and quarks of charge -13 do not belong to the same weak isomultiplets for at least one chirality. Special attention is given to a more restricted class of models in which (1) quarks of a given charge and chirality have the same weak isospin I and I3, and (2) quarks of charge q and quarks of charge q+1 do not belong to the same isomultiplets for at least one chirality. In such models, the electric dipole moment of a quark arises only in second-order weak interactions, and is estimated to be of order of 10-30 cm. Several examples of this class of models are given, one of which is the six-quark model of Kobayashi and Maskawa.
- Publication:
-
Physical Review D
- Pub Date:
- June 1977
- DOI:
- 10.1103/PhysRevD.15.3394
- Bibcode:
- 1977PhRvD..15.3394L