the $\mu$-term amplitude, to the “naive” scaling relation d\_i/d\_j = m\_i/m\_j    . \[naive\] Then, due to the present experimental limit on $d_e$, $d_\mu$ could not exceed $d_e m_\mu/m_e  \sim 2 \cdot 10^{-25}$ e cm, which roughly corresponds to the planned sensitivity and, if the limit on $d_e$ were still to be lowered, next generation experiments would have no chance of measuring $d_\mu$.

Such considerations could provide interesting informations because (\[naive\]) strictly apply only to the FC $\mu$-contribution to the EDM, while in general both ${\cal I}m (A_{ii})$ and the FV terms may strongly violate it. This is the case for the radiatively induced ${\cal I}m (A_{ii})$. Some of the FV contributions are instead naturally proportional to a different lepton mass, $m_k$, possibly heavier than $m_i$, as discussed in [@fms; @romstr] - and, before, for the quark sector, in [@bs]. In particular, it will turn out in the next sections that the FV contribution can even take over the FC one. Hence, a value of $d_\mu$ above $\sim 2 \cdot 10^{-25}$ e cm is a possibility that deserves experimental tests and, interestingly enough, it would imply the source of lepton EDM being either the FV contribution or a non-universal ${\cal I}m(A_{ii})$, 