中国物理学会高能物理分会第十三届全国粒子物理学术会议（2021）

One of the main goals of RHIC beam energy scan (BES) program is to search for the signatures of QCD critical point in heavy-ion collisions. It is predicted that the local density fluctuations near the critical point exhibit power-law scaling, which can be probed with an intermittency analysis of the scaled factorial moments, $F_{q}(M)$, for charged particles. The power-law behavior of $q^{th}$ order scaled factorial moments can be expressed as: $F_{q}(M)\sim F_{2}(M)^{\beta_{q}}$, where $M$ is the number of equally sized cells in one dimension of momentum space, and $\beta_{q}$ is the intermittency exponent. The scaling exponent, $\nu$, related to the critical component can be derived from the equation: $\beta_{q}\sim (q-1)^{\nu}$. The energy dependence of $\nu$ could be used to search for the signature of the QCD critical point. Similar measurements have been carried out by NA49 and NA61 experiments in heavy-ion collisions with different system sizes. In this talk, we will present the scaled factorial moments ($F_{q}(M)$, up to sixth order) of charged particles in Au + Au collisions at $\sqrt{s_{NN}}$ = 7.7 - 200 GeV measured by STAR experiment in the first phase of RHIC BES. Then, we will show the energy and centrality dependence of the extracted $\nu$ values. The physical implications of these results will be discussed.