Investigating the Event-Shape Methods in Search for the Chiral Magnetic Effect in Relativistic heavy-ion Collisions
Han-Sheng Li, Yicheng Feng, Fuqiang Wang
公開日: 2025/9/25
Abstract
The azimuthal correlator $\Delta\gamma$ searching for the chiral magnetic effect (CME) is contaminated by a major background proportional to the elliptic flow $v_2$. Event-shape engineering (ESE) and event-shape selection (ESS) binning events in {\em dynamical} and {\em statistical} fluctuations of $v_2$, respectively, are two methods searching for the CME. We conduct a systematic study using physics and toy model simulations. It is found that ESE fulfills the general premise of measuring the CME but is statistically hungry, whereas ESS is not practical to measure the CME because of the intertwining variables used in the method.