Determination of impact parameter in high-energy heavy-ion collisions via deep learning
Abstract
In this study, Au+Au collisions with the impact parameter of fm at GeV are simulated by the AMPT model to provide the preliminary final-state information. After transforming these information into appropriate input data (the energy spectra of final-state charged hadrons), we construct a deep neural network (DNN) and a convolutional neural network (CNN) to connect final-state observables with impact parameters. The results show that both the DNN and CNN can reconstruct the impact parameters with a mean absolute error about fm with CNN behaving slightly better. Then, we test the neural networks for different beam energies and pseudorapidity ranges in this task. It turns out that these two models work well for both low and high energies. But when making test for a larger pseudorapidity window, we observe that the CNN shows higher prediction accuracy than the DNN. With the method of Grad-CAM, we shed light on the `attention' mechanism of the CNN model.
Keywords
Cite
@article{arxiv.2112.03824,
title = {Determination of impact parameter in high-energy heavy-ion collisions via deep learning},
author = {Pei Xiang and Yuan-Sheng Zhao and Xu-Guang Huang},
journal= {arXiv preprint arXiv:2112.03824},
year = {2022}
}