  At hadron colliders, top quarks are dominantly produced in pairs
($t\bar{t}$), a production mechanism that was discovered more than twenty years
ago at the Tevatron in Fermilab. Although the \ttbar process has already
entered the domain of "precision" physics, especially with the advent of the
multi-TeV energies at the CERN LHC, there still remains room for dedicated
experimental measurements of the top quark in the "gap" of energies between
Tevatron and LHC. Hence, in the study presented here the total inclusive cross
section for pair production at a center-of-mass energy of 5.02 TeV is measured
having utilized a low-pileup proton-proton (pp) collision dataset whose
recorded luminosity by CMS amounts to 26 pb$^{-1}$. This work, has considered
only leptonic W decays, the latter characterized by the presence of an
energetic opposite-sign lepton pair plus missing energy. The current
measurement can be used for stronger constraints to the poorly known gluon
distribution inside the proton at large longitudinal parton momentum fraction,
while it paves the way for the very first observation of this elementary
particle in nucleus-nucleus collisions.
