Importance of the Volume Fluctuation Correction on Higher Order Cumulants

Abstract

Initial volume fluctuation (VF) caused by participant fluctuation would be the background which should be subtracted from experimentally measured higher-order cumulants. STAR experiment has been applied Centrality Bin Width Correction (CBWC) to suppress VF. However, CBWC is not perfect method, there might be thus residual fractions of VF backgrounds. Recently, Volume Fluctuation Correction (VFC) was developed under the assumption of the independent particle production (IPP) model. In this talk, the importance of subtracting VF and validity of the VFC are studied by using simple toy models assuming IPP as well as UrQMD model. The results showed that VFC worked well in toy model but did not work well in UrQMD which imply that IPP model could be broken in UrQMD.