  The hybridization between f-electrons and conduction band carriers ($V_{cf}$)
is essential for the heavy fermion behavior and may play an important role in
other fascinating phenomena such as quantum phase transitions or unconventional
superconductivity. In order to provide an insight into $V_{cf}$, systematic
studies of CeCoIn$_5$ heavy fermion superconductor have been performed by
angle-resolved photoemission spectroscopy (ARPES) in large angular range at
temperature of T=6 K. Calculations carried out with relativistic multiple
scattering KKR method and one-step model of photoemission yielded realistic
simulation of the ARPES spectra. Effects of the hybridization strongly depend
on wave vector. They include a dispersion of heavy f-electron band and a
coexistence of highly and weakly correlated carriers. We have also observed a
considerable variation of f-electron spectral weight at $E_F$, which is
normally determined by both the matrix element effects and wave vector
dependent $V_{cf}(k)$. Fermi surface scans covering a few Brillouin zones
revealed large matrix element effects. A symmetrization of experimental FS,
which reduces matrix element contribution, yielded a specific variation of
4f-electron spectral intensity at $E_F$ around $\bar{\Gamma}$ and $\bar{M}$
points, which is attributed to the effect of $V_{cf}$ hybridization. Tight
binding approximation calculations for Ce-In plane provided the same universal
distribution of 4f-electron density for a range of values of the parameters
used in the model. This proves that we were able to extract the effect of
$V_{cf}$ on f-electron intensity in ARPES spectra.
