Methods and Results on Conserved Charge Fluctuations from RHIC-BES and FXT*

One of the ultimate goals in heavy-ion collision experiments is to understand the QCD phase structure and the nature of the phase transition. At RHIC, cumulants up to the sixth-order of the net-particle multiplicity distributions have been measured for the Beam Energy Scan (BES) and fixed-target (FXT) program (2010-2017), from which some interesting hints on the phase structure have been obtained.

The higher-order cumulants are more sensitive not only to the QCD phase structure but also to the experimental artifacts such as detector efficiencies, initial volume fluctuations, and event pileups. In this talk, we will briefly discuss about the analysis techniques to overcome those issues. We will then present the experimental results from RHIC-BES and FXT [1-4], and current interpretations. We will also discuss about the importance of the p_T acceptance correction [5] and future measurements including hyperons [6].

References

[1] J. Adam et al., Phys. Rev. Lett., 126.092301(2021)

[2] Mohamed Abdallah et al., Phys. Rev. C, 104.024902(2021)

[3] M. S. Abdallah et al., Phys. Rev. Lett., 128.202303(2022)

[4] Mohamed Abdallah et al., Phys. Rev. Lett., 127.262301(2021)

[5] M. Kitazawa et al., Nucl.Phys.A 1030.122591(2023)

[6] T. Nonaka, Nucl.Instrum.Meth.A 1039.167171(2022)