φ meson production at RHIC Original Research Article

The production of φ mesons in Au+Au collisions at RHIC and their propagation in a hot and dense nuclear medium is studied within the microscopic quark-gluon string model. The inverse slope parameter of the transverse mass distribution agrees well with that extracted from the STAR data, while the absolute yield of φ is underestimated by a factor 2. It appears that the fusion of strings alone cannot increase the φ yield either. Less than 30% of detectable φʹs experience elastic scattering, this rate is insufficient for the full thermalization of φ. The directed flow of φ at ∣y∣≤ 2 demonstrates strong antiflow behavior, whereas its elliptic flow rises up to about 3.5% in the same rapidity interval. As a function of transverse momentum its rises linearly with increasing pt, in agreement with the STAR data, and saturates at pt > 2 GeV/c.