Global polarizations ($P$) of $\mathrm{\Lambda } \left(\overline{\mathrm{\Lambda }}\right)$ hyperons have been observed in noncentral heavy-ion collisions. The strong magnetic field primarily created by the spectator protons in such collisions would split the $\mathrm{\Lambda }$ and $\overline{\mathrm{\Lambda }}$ global polarizations ($\mathrm{\Delta }P=P_{\mathrm{\Lambda }}-P_{\overline{\mathrm{\Lambda }}}<0$). Additionally, quantum chromodynamics predicts topological charge fluctuations in vacuum, resulting in a chirality imbalance or parity violation in a local domain. This would give rise to an imbalance ($\mathrm{\Delta }n=\frac{N_{\text{L}}-N_{\text{R}}}{\langle N_{\text{L}}+N_{\text{R}}\rangle }\ne 0$) between left- and right-handed $\mathrm{\Lambda }$ ($\overline{\mathrm{\Lambda }}$) as well as a charge separation along the magnetic field, referred to as the chiral magnetic effect (CME). This charge separation can be characterized by the parity-even azimuthal correlator ($\mathrm{\Delta }\gamma$) and parity-odd azimuthal harmonic observable ($\mathrm{\Delta }{a}_1$). Measurements of $\mathrm{\Delta }P, \mathrm{\Delta }\gamma$, and $\mathrm{\Delta }{a}_1$ have not led to definitive conclusions concerning the CME or the magnetic field, and $\mathrm{\Delta }n$ has not been measured previously. Correlations among these observables may reveal new insights. This paper reports measurements of correlation between $\mathrm{\Delta }n$ and $\mathrm{\Delta }{a}_1$, which is sensitive to chirality fluctuations, and correlation between $\mathrm{\Delta }P$ and $\mathrm{\Delta }\gamma$ sensitive to magnetic field in $\mathrm{Au}+\mathrm{Au}$ collisions at 27 GeV. For both measurements, no correlations have been observed beyond statistical fluctuations.

• Received 20 April 2023
• Accepted 28 June 2023

DOI:https://doi.org/10.1103/PhysRevC.108.014909