May 17 – 22, 2021
US/Eastern timezone

Measurement of global polarization of $\Lambda$ hyperons in Au+Au $\sqrt{s_{\rm{NN}}}$ = 7.2 GeV Fixed-target collisions at RHIC-STAR experiment

May 20, 2021, 10:10 AM
Room B (Zoom)

Room B


zoom co-host: Klaus Dehmelt


Kosuke Okubo (University of Tsukuba)


Non-central heavy-ion collisions produce a large angular momentum that leads to vorticity of the created system. Due to the spin-orbit coupling, spin directions
of particles are aligned with the orbital angular momentum of the system. Global
polarization of $\Lambda$ and $\bar{\Lambda}$ hyperons has been measured in Au+Au collisions from $\sqrt{s_{\rm{NN}}}$ = 7.7 GeV to 200 GeV[1][2]. The STAR fixed target program provides an opportunity to extend such measurements at even lower energies. Additionally, $\Lambda$ global polarization is also influenced by magnetic field at the initial stage. It would be interesting to investigate such effects towards lower beam energies. In this talk, measurement of global polarization of $\Lambda$ hyperons in Au+Au collisions at $\sqrt{s_{\rm{NN}}}$ = 7.2 GeV with the fixed-target configuration is reported.

[1] L.Adamczyk et al,(STAR) Nature 548 62 (2017).
[2] J.Adam et al.(STAR), Phys. Rev. C 98 14910 (2018)

Collaboration STAR Collaboration

Presentation materials