Lepton flavor violation andθ13in minimal resonant leptogenesis

Abstract

We study the impact of minimal nonsupersymmetric models of resonant leptogenesis on charged-lepton flavor violation and the neutrino-mixing angle 13 . Possible low-scale flavor realizations of resonant -, -and e-leptogenesis provide very distinct and predictive frameworks to explain the observed baryon asymmetry in the Universe by sphaleron conversion of an individual -, -and e-lepton-number asymmetry which gets resonantly enhanced via out-of-equilibrium decays of nearly degenerate heavy Majorana neutrinos. Based on approximate flavor symmetries, we construct viable scenarios of resonant -, -and e-leptogenesis compatible with universal right-handed neutrino masses at the grand unified theory scale, where the required heavy-neutrino mass splittings are generated radiatively. The heavy Majorana neutrinos in such scenarios can be as light as 100 GeV and their couplings to two of the charged leptons may be large. In particular, we explicitly demonstrate the compelling role that the three heavy Majorana neutrinos play, in order to obtain successful leptogenesis and experimentally testable rates for lepton-flavor violating processes, such as ! e and ! e conversion in nuclei.

Muon conversion to electron in nuclei in type-I seesaw models

“…For the former (unlike for the latter) our results agree with those in Ref. [16] (and in Ref. [15] provided one takes the nonsupersymmetric limit of the results quoted there).…”

“…Our results agree with the sign indicated in Refs. [11,15,16], and is opposite to that in Refs. [12,13].…”

“…We get different results for them, though, than in Ref. [16], where some of them have been neglected. On the contrary, our results agree with the full expressions for those form factors given in in Ref.…”

“…(3.21) of Ref. [16] by two orders of magnitude. signs, as an outcome of their different charge and weak isospin.…”

“…The µ → e conversion rate R µ→e has been calculated in the literature for the various possible types of seesaw, with right-handed neutrinos [10][11][12][13][14][15][16], scalar triplet(s) [17][18][19] and fermion triplets [20]. For the right-handed neutrino case ("type-I" seesaw), a comparison of the various calculations shows that there is no agreement on what is actually the result.…”