# Bulk Properties of the System Formed in Au+Au Collisions at $\sqrt{s_{\mathrm{NN}}}$ = 14.5 GeV

## TL;DR

This paper presents systematic measurements of bulk properties in Au+Au collisions at 14.5 GeV, including particle spectra and flow, filling a gap in energy dependence studies relevant for understanding the quark-gluon plasma.

## Contribution

It provides new experimental data at 14.5 GeV, bridging the gap between lower and higher energies, and compares results with models, highlighting discrepancies.

## Key findings

- Results follow established energy dependence trends.
- Poor agreement with UrQMD and AMPT models.
- Fills gap in baryon chemical potential studies.

## Abstract

We report systematic measurements of bulk properties of the system created in Au+Au collisions at $\sqrt{s_{\mathrm{NN}}}$ = 14.5 GeV recorded by the STAR detector at the Relativistic Heavy Ion Collider (RHIC).The transverse momentum spectra of $\pi^{\pm}$, $K^{\pm}$ and $p(\bar{p})$ are studied at mid-rapidity ($|y| < 0.1$) for nine centrality intervals. The centrality, transverse momentum ($p_T$),and pseudorapidity ($\eta$) dependence of inclusive charged particle elliptic flow ($v_2$), and rapidity-odd charged particles directed flow ($v_{1}$) results near mid-rapidity are also presented. These measurements are compared with the published results from Au+Au collisions at other energies, and from Pb+Pb collisions at $\sqrt{s_{\mathrm{NN}}}$ = 2.76 TeV. The results at $\sqrt{s_{\mathrm{NN}}}$ = 14.5 GeV show similar behavior as established at other energies and fit well in the energy dependence trend. These results are important as the 14.5 GeV energy fills the gap in $\mu_B$, which is of the order of 100 MeV,between $\sqrt{s_{\mathrm{NN}}}$ =11.5 and 19.6 GeV. Comparisons of the data with UrQMD and AMPT models show poor agreement in general.