  The theoretical model for the quasiparticle self-energy in HTSC is proposed,
which is based on the forward scattering peak in the electron-phonon (EPI)
interaction. By assuming that EPI dominates, the model explains qualitatively
and in a consistent way the recent ARPES results. The latter show a kink in the
normal state quasiparticle energy at 70 meV in the nodal direction, which is
(surprisingly) not shifted in the superconducting (SC) state, while the
singularity at 40 meV in the anti-nodal direction is shifted by the SC gap. The
model predicts a dip-hump structure in the spectral function, which is observed
in ARPES.
