Chiral Representation Research Articles

CPViolation and Chiral Symmetry

$\mathrm{CP}$-violation terms belonging to the (3,${3}^{*}$) and (3,${3}^{*}$) chiral representations are discussed with the help of a general form of the SU (3) $\ensuremath{\sigma}$ model. We develop the formalism for calculation with such terms and proceed to numerical estimates. It is noted that the electric dipole moment of the neutron may be calculated very simply in this approach and the results show that models of this type are unlikely. The question of spontaneous breakdown of $\mathrm{CP}$ invariance is also discussed. As an aside it is shown that both $\mathrm{CP}$-violating and $\mathrm{CP}$-conserving $|\ensuremath{\Delta}S|=1$ terms of the ("3,${3}^{*}$") type do not contribute to nonleptonic decays. Thus the socalled tadpole corrections to hyperon decays really vanish.

Baryon Excitation Form Factors and Asymptotic Chiral Symmetry

An explicit multipole decomposition of the vector and pseudovector $N\ensuremath{-}{N}^{*}(1236)$ transition form factors is made, and the predictions of asymptotic chiral symmetry are discussed. A general consistency between the chiral predictions and the simplest assumptions on multipole behavior is found for one choice of decuplet chiral representation.

Partial Conservation of Axial-Vector Current and Chiral Representation Mixing

Partial Conservation of Axial-Vector Current and Chiral Representation Mixing