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In heavy-ion collisions, the observation of the global hyperon polarization, $\overline{P}_\mathrm{H}$, ranging from $\sqrt{s_\mathrm{NN}}=7.7$~GeV to 5.02~TeV has revealed the existence of large vorticities perpendicular to the reaction plane due to system's orbital angular momentum. We present recent results on $\overline{P}_\mathrm{H}$, and differential measurements thereof, extended to the low energies of 3 and 7.2~GeV~[1]. A notable advantage of the STAR acceptance at low $\sqrt{s_\mathrm{NN}}$ is the ability to measure the dependence of $\overline{P}_\mathrm{H}$ on $y$ across the full range of hyperon production in $y$ which can test the predictions of numerous model calculations. Further studies of differential measurements of $\overline{P}_\mathrm{H}$ are presented as well using Au+Au collisions at $\sqrt{s_\mathrm{NN}}=19.6$ and $27$~GeV which allow for comparisons to the low-$\sqrt{s_\mathrm{NN}}$ measurements presented here and to the high-energy measurements studied in Ref.~[2]. Studies of the vortical flow structure's dependence on system size are also possible using Ru+Ru and Zr+Zr collisions at $\sqrt{s_\mathrm{NN}}=200$~GeV which are presented here as well. Furthermore, while $\overline{P}_\mathrm{H}$ reveals information about the vorticity driven by angular momentum, a recent study~[3] measuring local polarization along the beam direction, $\overline{P}_\mathrm{Z}$, revealed vorticity in the QGP arising from collective flow. The measurement stands in disagreement with a number of model calculations and, to shed light on the matter, measurements of $\overline{P}_\mathrm{Z}$ can be conducted in smaller systems than Au+Au or relative to higher-order event-plane angles. These measurements of $\overline{P}_\mathrm{Z}$ in Ru+Ru and Zr+Zr at $\sqrt{s_\mathrm{NN}}=200$~GeV presented here will provide valuable insight into the mechanisms of flow-driven vorticity.
[1]~M. S. Abdallah et al. Global $\Lambda$-hyperon polarization in Au+Au collisions at $\sqrt {s_{\rm NN}}$=3~GeV. {\it Phys. Rev. C}, 104(6):L061901, 2021.
[2]~J. Adam et al. Global polarization of $\Lambda$ hyperons in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV. {\it Phys. Rev. C}, 98:014910, 2018.
[3]~J. Adam et al. Polarization of $\Lambda$ ($\bar{\Lambda}$) hyperons along the beam direction in Au+Au collisions at $\sqrt{s_{_{NN}}}$ = 200 GeV. {\it Phys. Rev. Lett.}, 123(13):132301,2019.
