  The temperature-dependent mass of the heavy neutrino can lead to the second
leptogenesis occurring below the electroweak scale, potentially explaining the
large discrepancy between baryon and lepton asymmetries. We investigate this
scenario further, exploring the intricate interplay of the weak interaction
processes within this framework. It includes notable shifts in the dominant
decay channels of heavy neutrinos around the electroweak symmetry breaking,
along with the resonance behavior of the scattering processes near the $W/Z$
mass. The $CP$ asymmetry can also vary over cosmic history due to the
temperature-dependent mass, allowing the $B-L$ asymmetry generation to be
amplified in the late epoch. These findings elucidate how such alterations in
the dynamics of second leptogenesis contribute to addressing the observed
discrepancies in baryon-lepton asymmetry.
