Year: 1999
Type: article
Abstract: Physics beyond the standard model of electroweak interactions that violates lepton number will, in general, induce operators involving the quark and lepton fields that violate lepton number. I point out that some matrix elements of particular operators are known. In the limit of exact SU(3) flavor symmetry the operator $\ifmmode \bar{u}\else \={u}\fi{}{\ensuremath{\gamma}}_{\ensuremath{\mu}}(1\ensuremath{-}{\ensuremath{\gamma}}_{5})d\ifmmode \bar{u}\else \={u}\fi{}{\ensuremath{\gamma}}_{\ensuremath{\mu}}(1\ensuremath{-}{\ensuremath{\gamma}}_{5})d$ is part of the $27$ representation responsible for $\ensuremath{\Delta}I=\frac{3}{2}$ strangeness changing decays in the standard model. At leading order in the chiral expansion there is only one coupling constant that describes the weak interactions of the pseudo-Goldstone bosons induced by the $27$ representation. The observed branching fraction for ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{0}$ determines this coupling constant. Contributions of the form ${m}_{s}\mathrm{ln}{m}_{s}$ are used to estimate SU(3) breaking corrections to the relation between ${K}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{0}$ and the ${\ensuremath{\pi}}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{e}^{\ensuremath{-}}{e}^{\ensuremath{-}}$ interaction.
Source: Physical Review C
Author: Martin J. Savage
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2044413839