  Angle-resolved photoemission spectroscopy (ARPES) is used to study the energy
and momentum dependence of the inelastic scattering rates and the mass
renormalization of charge carriers in LiFeAs at several high symmetry points in
the Brillouin zone. A strong and linear-in-energy scattering rate is observed
for sections of the Fermi surface having predominantly Fe $3d_{xy/yz}$ orbital
character on the inner hole and on electron pockets. We assign them to hot
spots with marginal Fermi liquid character inducing high antiferromagnetic and
pairing susceptibilities. The outer hole pocket, with Fe $3d_{xy}$ orbital
character, has a reduced but still linear in energy scattering rate. Finally,
we assign sections on the middle hole pockets with Fe $3d_{xz,yz}$ orbital
character and on the electron pockets with Fe $3d_{xy}$ orbital character to
cold spots because there we observe a quadratic-in-energy scattering rate with
Fermi-liquid behavior. These cold spots prevail the transport properties. Our
results indicate a strong $\it{momentum}$ dependence of the scattering rates.
We also have indications that the scattering rates in correlated systems are
fundamentally different from those in non-correlated materials because in the
former the Pauli principle is not operative. We compare our results for the
scattering rates with combined density functional plus dynamical mean-field
theory calculations. The work provides a generic microscopic understanding of
macroscopic properties of multiorbital unconventional superconductors.
