Multi-particle cumulants and corresponding
Fourier harmonics are measured for azimuthal angle distributions
of charged particles in pp collisions at √s = 5.02 and
13 TeV and in p + Pb collisions at √sNN = 5.02 TeV, and compared
to the results obtained for low-multiplicity Pb + Pb
collisions at √sNN = 2.76 TeV. These measurements aim to
assess the collective nature of particle production. The measurements
of multi-particle cumulants confirm the evidence
for collective phenomena in p + Pb and low-multiplicity
Pb + Pb collisions. On the other hand, the pp results for fourparticle
cumulants do not demonstrate collective behaviour,
indicating that they may be biased by contributions from nonflow
correlations. A comparison of multi-particle cumulants
and derived Fourier harmonics across different collision systems
is presented as a function of the charged-particle multiplicity.
For a given multiplicity, the measured Fourier harmonics
are largest in Pb + Pb, smaller in p + Pb and smallest
in pp collisions. The pp results show no dependence on the
collision energy, nor on the multiplicity.