2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/194730We have studied a leptogenesis scenario in the framework of the minimal seesaw model with tri/bi-maximal mixing. Usually, at least one of the elements in the Dirac mass matrix is fixed to be zero, for example, we denote it by $b_2=0$. We have pointed out that the absolute value of the CP asymmetry has several minimums and maximums with non-zero $b_2$. Thus one can expect that more rich phenomena, such as an enhanced leptogenesis, are hidden in the $b_2 \neq 0$ space.9 pages, 7 figures, uses RevTex4. To appear in Physcal Review DHigh Energy Physics - Phenomenologytext