  The existence and location of the QCD critical point is an object of both
experimental and theoretical studies. The comprehensive data collected by
NA61/SHINE during a two-dimensional scan in beam momentum (13A-150A GeV/c) and
system size (p+p, p+Pb, Be+Be, Ar+Sc, Xe+La, Pb+Pb) allows for a systematic
search for the critical point-a search for a non-monotonic dependence of
various correlation and fluctuation observables on collision energy and size of
colliding nuclei. In particular, fluctuations of particle number in transverse
momentum space are studied. They are quantified by measuring the scaled
factorial moments of multiplicity distribution.
