Light Nuclei Femtoscopy and Baryon Interactions in 3 GeV Au+Au Collisions at RHIC

TL;DR

This paper presents the first measurements of proton-deuteron and deuteron-deuteron correlation functions in 3 GeV Au+Au collisions at RHIC, extracting source sizes and interaction parameters, and confirming the nucleon coalescence model.

Contribution

It introduces the first extraction of source size, scattering length, and effective range from femtoscopy measurements in low-energy heavy-ion collisions.

Findings

Measured $p$-$d$ and $d$-$d$ correlation functions at 3 GeV Au+Au collisions.

Extracted interaction parameters consistent with theoretical and experimental results.

Demonstrated the feasibility of femtoscopy for baryon interaction studies in heavy-ion collisions.

Abstract

We report the measurements of proton-deuteron ($p$-$d$) and deuteron-deuteron ($d$-$d$) correlation functions in Au+Au collisions at $\sqrt{s_\mathrm{NN}}$ = 3 GeV using fixed-target mode with the STAR experiment at the Relativistic Heavy-Ion Collider (RHIC). For the first time, the source size ($R_{G}$), scattering length ($f_{0}$), and effective range ($d_{0}$) are extracted from the measured correlation functions with a simultaneous fit. The spin-averaged $f_0$ for $p$-$d$ and $d$-$d$ interactions are determined to be -5.28 $\pm$ 0.11(stat.) $\pm$ 0.82(syst.) fm and -2.62 $\pm$ 0.02(stat.) $\pm$ 0.24(syst.) fm, respectively. The measured $p$-$d$ interaction is consistent with theoretical calculations and low-energy scattering experiment results, demonstrating the feasibility of extracting interaction parameters using the femtoscopy technique. The reasonable agreement between the experimental data and the calculations from the transport model indicates that deuteron production in these collisions is primarily governed by nucleon coalescence.