# Constructing probability density function of net-proton multiplicity distributions using Pearson curve method

## TL;DR

This paper constructs probability density functions of proton, anti-proton, and net-proton multiplicity distributions using the Pearson curve method, revealing potential signatures of O(4) criticality in heavy-ion collision data.

## Contribution

It introduces a novel application of the Pearson curve method to model multiplicity distributions and compares them with theoretical baselines to identify critical phenomena.

## Key findings

- Some signatures of O(4) criticality are observed.
- Constructed PDFs provide a baseline for future cumulant measurements.
- Comparison with Skellam and Binomial distributions highlights deviations near criticality.

## Abstract

The probability density functions of proton, anti-proton, and net-proton multiplicity distributions are constructed from the Beam Energy Scan results of the STAR experiment using the Pearson curve method. The constructed distributions of proton and anti-proton are compared with Poisson and Binomial distributions. The net-proton probability distributions are compared with Skellam distributions to study the O(4) criticality near the chiral crossover transition. The $C_{6}/C_{2}$ results estimated from the obtained PDFs are compared with Skellam and Binomial baselines for the Beam Energy Scan data. The current study shows some signatures of O(4) criticality, which can be further investigated by precision measurements of the cumulants and understanding the contribution of non-critical fluctuations to them. This study also provides a baseline for the higher-order cumulant measurement in the upcoming RHIC BES II program and future LHC run.