Speaker
Description
$\phi$ has relatively small hadronic interaction cross sections and it can be used to study the properties of nuclear medium at the early stage. The recombination model indicates that the $\Omega/\phi$ ratio will be enhanced at low and medium transverse momentum $(p_{\text{T}})$, where thermal strange quarks dominate the production of $\Omega$ and $\phi$ in the QGP. Therefore, the multi-strange baryon-to-meson ratio $\Omega({sss})/\phi({s\bar{s}})$ is proposed to be a sensitive probe for studying the onset of deconfinement. Because the STAR Beam Energy Scan Phase ΙΙ (BES ΙΙ) program has 10 times larger data size than BESΙ and explore the QCD phase diagram in a region which may cover the potential critical point, it offers us a great opportunity to investigate collision energy and system size dependence of $\phi$ production in heavy-ion collisions.
In this report, we present new measurements on $p_{\text{T}}$ spectra, centrality dependence of $\phi$ production yields (dN/dy), resonance to non-resonance yield ratio $(\phi/K^{-})$, nuclear modification factor $(R_{\text{CP}})$, the rapidity spectra and $\Omega({sss})/\phi({s\bar{s}})$ ratio in Au+Au collisions at $\sqrt{s_{NN}}$ = 7.7, 14.6 and 19.6 GeV. Physics implications of these measurements will be discussed.
