Nonflow suppression in flow analysis with a maximum likelihood estimator
Phys. Rev. C 113, 044912 – Published 17 April, 2026
DOI: https://doi.org/10.1103/pc29-yh5l
Abstract
We show that the maximum likelihood estimator (MLE) is an effective tool for mitigating nonflow effects in flow analysis. To this end, one constructs two toy models that simulate nonflow contributions corresponding to particle decay and momentum conservation, respectively. The performance of MLE is analyzed by comparing it against standard approaches such as particle correlation and event plane methods. For both cases, MLE is observed to provide a reasonable estimate of the underlying flow harmonics, and, in particular, its performance can be further improved when the specific form of the likelihood in the presence of nonflow can be assessed. The dependencies of extracted flow harmonics on the multiplicity of individual events and the total number of events are analyzed. Additionally, it is shown that the proposed approach performs efficiently in addressing deficiencies in detector acceptance. These findings suggest that MLE is a compelling alternative to standard methods for flow analysis.
