Speaker
Ms
Elke Aeikens
(University Vienna)
Description
Extensions of the Standard Model with right-handed neutrinos $\nu_R$
in the framework of the seesaw mechanism are popular to explain the smallness of the neutrino masses.
In our model, we add a second Higgs double and in order to avoid
lepton flavour-changing neutral-scalar interactions at tree level, we allow lepton flavour violation solely in the non-flavour-diagonal Majorana mass matrix of the right-handed neutrinos whereas all Yukawa-coupling matrices are lepton flavour-diagonal.
We show explicitly in that framework that the branching ratios of the charged-lepton decays
$\ell_1^- \to \ell_2^- \ell_3^+ \ell_3^-$
can be close to their experimental upper bounds,
while the branching ratios of other lepton flavour-changing decays, like $\ell_1\rightarrow \ell_2 \gamma$,
are invisible because they are suppressed by $m_R^{-4}$,
where $m_R$ is the seesaw scale.
Furthermore, considering the anomalous magnetic moment of the muon, in our model the contributions from the extra scalars
can remove the discrepancy between its experimental and theoretical values.
Primary authors
Ms
Elke Aeikens
(University Vienna)
Prof.
Luis Lavoura
(CFTP, Instituto Superior Tecnico, Universidade de Lisboa)
Prof.
Walter Grimus
(University of Vienna)