  The $m_T$-dependencies of the femto-scales, the so-called interferometry and
source radii, are investigated within the hydrokinetic model for different
types of particle pairs - pion-pion, kaon-kaon, proton-proton and
proton-lambda, - produced in Pb+Pb and $p+p$ collisions at the LHC. In
particular, such property of the femto-scales momentum behavior as
$m_T$-scaling is studied for the systems with (w) and without (w/o) intensive
transverse flow, and also w and w/o re-scattering at the final afterburner
stage of the matter evolution. The detail spatiotemporal description obtained
within hydrokinetic model is compared with the simple analytical results for
the spectra and longitudinal interferometry radii depending on the effective
temperature on the hypersurface of maximal emission, proper time of such
emission, and intensity of transverse flow. The derivation of the corresponding
analytical formulas and discussion about a possibility for their utilization by
the experimentalists for the simple femtoscopy data analysis is the main aim of
this theoretical investigation.
