Search for CME in U+U and Au+Au collisions in STAR with different approaches of handling backgrounds

Understand

The chiral magnetic effect (CME) refers to charge separation along a strong magnetic field between left- and right-handed quarks, caused by interactions with topological gluon fields from QCD vacuum fluctuations.

• We present two approaches to handle the dominant elliptic flow ($v_2$) background in the three-particle correlator ($\Delta\gamma_{112}$), sensitive to CME.
• In the first approach, we present the $\Delta\gamma_{112}$ and $\Delta\gamma_{123}$ measurements in U+U and Au+Au collisions.
• While hydrodynamic simulations including resonance decays and local charge conservation predict that $\Delta\gamma_{112}$ scaled by $N_{\rm part}/v_2$ will be similar in U+U and Au+Au collisions, the projected B-field exhibits a distinct difference between the two systems and with varying $N_{\rm part}$.