Imaging Freeze-Out Sources and Extracting Strong Interaction Parameters in Relativistic Heavy-Ion Collisions
Junhuai Xu, Zhi Qin, Rui Zou, Dawei Si, Sheng Xiao, Baiting Tian, Yijie Wang, Zhigang Xiao
Abstract
Abstract By combining femtoscopic interferometry with an optical deblurring algorithm, we present a novel method to image the source in heavy-ion collisions (HICs), while simultaneously determining the interaction strength between particle pairs. The spatial distribution of the emission source has been reconstructed for protons ( p ) and antiprotons ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mover accent="true"> <mml:mi>p</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> ) from the respective pp and <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mover accent="true"> <mml:mi>p</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> <mml:mover accent="true"> <mml:mi>p</mml:mi> <mml:mo>¯</mml:mo> </mml:mover> </mml:mrow> </mml:math> correlation functions in Au+Au collisions at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msqrt> <mml:mrow> <mml:msub> <mml:mi>S</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">NN</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:msqrt> <mml:mo>=</mml:mo> <mml:mn>200</mml:mn> </mml:mrow> </mml:math> GeV. Within experimental uncertainties, protons and antiprotons share the same freeze-out distribution showing higher density in the center compared to the widely assumed Gaussian shape. The results evidence the matter–antimatter symmetry in coordinate space at the freeze-out moment before the nucleons are fully randomized in the collisions.