| Summary: | Abstract We present a systematic study of leptogenesis in neutrino mass models with μτ-flavoured CP symmetry. In addition to the strong hierarchical N1-dominated scenario (N 1DS) in the ‘two flavour regime’ of leptogenesis, we show that one may choose the right-handed (RH) neutrino mass hierarchy as mild as M 2 ≃ 4.7M 1 for a perfectly valid hierarchical N 1DS. This reduces the lower bound on the allowed values of M 1, compared to what is stated in the literature. The consideration of flavour effects due to the heavy neutrinos also translate into an upper bound on M 1. It is only below this bound that the observed baryon-to-photon ratio can be realized for a standard N 1 domination, else a substantial part of the parameter space is also compatible with N 2DS. We deduce conditions under which the baryon asymmetry produced by the second RH neutrino plays an important role. Finally, we discuss another scenario where lepton asymmetry generated by N 2 in the two flavour regime faces washout by N 1 in the three flavour regime. Considering a hierarchical light neutrino mass spectrum, which is now favoured by cosmological observations, we show that at the end of N 1-leptogenesis, the asymmetry generated by N 2 survives only in the electron flavour and about 33% of the parameter space is consistent with a pure N 2-leptogenesis.
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