arXiv subjects
Publications and source records attributed to D. S. Shaw.
In recent years a new potential symmetry of fundamental particle physics has been investigated --- discrete quark-lepton symmetry. When this symmetry is implemented, however, it often leads to either of the unrealistic predictions $m_{u}=m_{e}$ or $m_{d}=m_{e}$. This paper considers two possible ways models based on $m_{d}=m_{e}$ can be made realistic.
An effective theory is proposed, combining the standard gauge group $SU(3)_{C}\otimes SU(2)_{L}\otimes U(1)_{Y}$ with a horizontal discrete symmetry. By assigning appropriate charges under this discrete symmetry to the various fermion fields and to (at least) two Higgs doublets, the broad spread of the fermion mass and mixing angle spectrum can be explained as a result of suppressed, non-renormalisable terms. A particular model is constructed which achieves the above while simultaneously suppressing neutral Higgs-induced flavour-changing processes.