  The extreme conditions of temperature and density produced in
ultrarelativistic collisions of heavy nuclei facilitate the formation of the
most fundamental fluid in the universe, the deconfined phase of Quantum
Chromodynamics called quark-gluon plasma. Despite the extensive experimental
evidence collected over the past decade of its production in colliding systems
such as Au-Au and Pb-Pb, establishing quark-gluon plasma formation in the
collision of smaller systems, such as p-Pb, remains an open question. In this
study, we describe the evolution of matter formed in p-Pb collisions at 5.02
TeV using a state-of-the-art hybrid model based on viscous relativistic
hydrodynamics. We investigate the thermodynamic properties of the medium and
final state observables. Our findings are compared with experimental data and
first-principles calculations derived from lattice quantum chromodynamics. The
results support the formation of a collective phase of strongly interacting
matter in high-multiplicity p-Pb collisions.
