Rare tau decays via exchange of on-shell almost degenerate Majorana neutrinos, ${\tau }^{\mp }\to {\pi }^{\mp }{N}_j\to {\pi }^{\mp }{\mu }^{\mp }{\pi }^{\pm }$ and ${\tau }^{\mp }\to {\pi }^{\mp }{N}_j\to {\pi }^{\mp }{\mu }^{\pm }{\pi }^{\mp }$

Gorazd Cvetic, C. S. Kim

We investigate rare decays of tau leptons that occur via exchange of heavy on-shell neutrinos $N_j$ ($j=1,2$). These neutrinos can be either Dirac or Majorana, and are considered t…