Reconstructing particle number distributions with convoluting volume fluctuations

We propose methods to reconstruct particle distributions with and without considering initial volume fluctuations. This approach enables us to correct for detector efficiencies and initial volume fluctuations simultaneously. Our study suggests such a tool could investigate the possible bimodal structure of net-proton distribution in Au+Au collisions at $sqrt{s_{rm NN}}=$7.7 GeV a signature of first-order phase transition and critical point [arXiv:1804.04463,arXiv:1811.04456].