A sensitivity study of the primary correlators used to characterize chiral-magnetically-driven charge separation
Niseem Magdy (1) · Mao-Wu Nie (2,3) · Guo-Liang Ma (3,4) · Roy A. Lacey (5) · ((1) Department of Physics, University of Illinois at Chicago, Chicago Illinois, USA, (2) Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao, Shandong, China (3) Key Laboratory of Particle Physics and Particle Irradiation, Ministry of Education, Shandong University, Qingdao, Shandong, China, (4) Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai, China, (5) Depts. of Chemistry and Physics, Stony Brook University, Stony Brook, New York, USA)
A Multi-Phase Transport (AMPT) model is used to study the detection sensitivity of two of the primary correlators -- and -- employed to characterize charge separation induced by the Chiral Magnetic Effect (CME). The study, performed relative to several event planes for different input "CME signals", indicates a detection threshold for the fraction , which renders the -correlator insensitive to values of the Fourier dipole coefficient , that is larger than the purported signal(signal difference) for ion-ion(isobaric) collisions. By contrast, the correlator indicates concave-shaped distributions with inverse widths () that are linearly proportional to , and independent of the character of the event plane used for their extraction. The sensitivity of the correlator to minimal CME-driven charge separation in the presence of realistic backgrounds, could aid better characterization of the CME in heavy-ion collisions.