Speaker
Description
Several Beyond the Standard Model scenarios introduce new heavy neutrinos, whose Dirac or Majorana nature could be tested by comparing the rates of lepton number violating and conserving processes: a Dirac fermion induces only the latter, while a Majorana one predicts the same ratio for both of them. Nevertheless, in presence of more than one Majorana fermion, this picture may change drastically due to interference effects. In this talk, we will focus on LNV and LFV semileptonic meson decays induced by two heavy Majorana fermions, exploring the necessary conditions to have sizable interference effects and discussing its implications for current experimental constraints and possible future observations. In particular, we show how the CP violating phases may lead to have an enhancement of the lepton number violating modes and suppression of the lepton number conserving ones, and vice-versa.
