N$_{i}$ N$_{i}$ N$_{i}$ N$_{j}$ N$_{j}$ ℓ$_{α}$ ℓ$_{α}$ ℓ$_{β}$ η ∗ η ∗ + + η η ∗ ℓ$_{β}$ ℓ$_{α}$ η FIG. 7: Decay of N$_{i}$ into ℓ$_{αL}$ and η . lepton flavor α (= e, µ, τ ), by [20, 21] where the function g ( x ) is given by Here i denotes a generation index and Γ( N$_{i}$ → · · · ) is the decay width of the i th-generation right-handed neutrino. Note that in our scenario the CP asymmetry is generated by ex- plicitly breaking the tri-bimaximal as in Eq. (8) when x is different from zero. Below temperature T ∼ M$_{i}$ ≲ 10 5 GeV, it is known that electron, muon and tau charged lepton Yukawa interactions are much faster than the Hubble expansion parameter rendering the e , µ and τ Yukawa couplings in equilibrium. Then, the processes which wash out lepton num- ber are flavor dependent and thus the lepton asymmetries for each flavor should be treated separately with different wash-out factors. Once the initial values of ε α i are fixed, the final result of η$_{B}$ or Y$_{B}$ can be obtained by solving a set of flavor-dependent Boltzmann equations including the decay, inverse decay, and scattering processes as well as the nonperturbative sphaleron interaction. In order to estimate the wash-out effects, we introduce the parameters K α i which are the wash-out factors due to the inverse decay of the Majorana neutrino N$_{i}$ into the lepton flavor α (= e, µ, τ ) [24]. The explicit form of K α i is given by 19 K α i = Γ( N$_{i}$ → ηℓ$_{α}$ ) H ( M$_{i}$ ) = K$_{i}$ ( ˜ Y ∗ ν )$_{αi}$( ˜ Y$_{ν}$ )$_{αi}$ ( ˜ Y † ν ˜ Y$_{ν}$ )$_{ii}$ , (39) g ( x ) = $^{√$_{x}$}$[ 1 1 − x + 1 − (1 + x )ln 1 + x x ] . (38) ε α i = Γ( N$_{i}$ → ℓ$_{α}$η ) − Γ( N$_{i}$ → ℓ$_{α}$η † ) ∑ $_{α}$[Γ( N$_{i}$ ℓ$_{α}$η ) + Γ( N$_{i}$ ℓ$_{α}$η † )] = 1 8 π ( ˜ Y † ν ˜ Y$_{ν}$ )$_{ii}$ ∑ j = i Im { ( ˜ Y † ν ˜ Y$_{ν}$ )$_{ij}$( ˜ Y$_{ν}$ $_{)}$∗ $_{αi}$( ˜ Y$_{ν}$ )$_{αj}$ } g ( M 2 j M 2 i ) , (37)