Speaker
Description
The deconfined state of strongly interacting quarks and gluons, quark-gluon plasma, may be formed in relativistic ion collisions at sufficient temperature and energy density. The signatures of quark-gluon plasma formation were observed in heavy-ion collisions by studying $\phi$ meson production. In small-collision systems, such as p+Al, p+Au, d+Au, and $^3$He+Au, the volume and lifetime of the produced medium might be insufficient for observation of quark-gluon plasma effects. However various physics mechanisms reflecting initial state of the collision, cold nuclear matter effects, may lead to a collective-like behaviour in small-collision systems without quark-gluon plasma formation. The nuclear modified parton distribution functions are considered to be an underlying physics mechanism of cold nuclear matter effects. This talk presents the comparison of $\phi$ meson production in p+Al, p+Au, d+Au, and $^3$He+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV at midrapidity ($|\eta|<0.35$), measured by PHENIX, to PYTHIA calculations with nuclear modified parton distribution functions EPPS16 and nCTEQ15. It has been shown that $\phi$ meson production in p/d/$^3$He+Au collisions at $\sqrt{s_{NN}}$ = 200 GeV might be driven by mechanisms additional to nuclear modification of parton distributions.
