CP Violation with Majorana neutrinos in K Meson Decays

Understand

We study the possibility of having CP asymmetries in the decay Kaon(+/-) -> pion(-/+) lepton(+/-) lepton(+/-) (lepton = muon or electron).

• This decay violates Lepton Number by two units and occurs only if there are Majorana particles that mediate the transition.
• Even though the absolute rate is highly suppressed by current bounds, we search for Majorana neutrino scenarios where the CP asymmetry arising from the lepton sector could be sizeable.
• This is indeed the case if there are two or more Majorana neutrinos with similar masses in the range around 10^2 MeV.