Nucleon momentum distribution of $^{56}\text{Fe}$ from the axially deformed relativistic mean-field model with nucleon--nucleon correlations

TL;DR

This paper investigates the nucleon momentum distribution in $^{56}$Fe using an axially deformed relativistic mean-field model, incorporating nucleon-nucleon correlations to match experimental high-momentum data and analyze relativistic effects.

Contribution

It introduces a method to include nucleon-nucleon correlations into the relativistic mean-field model for heavy nuclei, enhancing the understanding of high-momentum components.

Findings

High-momentum components agree with experimental data when NN correlations are included.

Deformation effects influence the NMD below the Fermi momentum.

Relativistic effects significantly impact the momentum space structure of nuclei.

Abstract

Nucleon momentum distribution (NMD), particularly its high-momentum components, is essential for understanding the nucleon--nucleon ($ NN $) correlations in nuclei. Herein, we develop the studies of NMD of $^{56}\text{Fe}$ from the axially deformed relativistic mean-field (RMF) model. Moreover, we introduce the effects of $ NN $ correlation into the RMF model from phenomenological models based on deuteron and nuclear matter. For the region $ k<k_{\text{F}} $, the effects of deformation on the NMD of the RMF model are investigated using the total and single-particle NMDs. For the region $ k>k_{\text{F}} $, the high-momentum components of the RMF model are modified by the effects of $ NN $ correlation, which agree with the experimental data. Comparing the NMD of relativistic and non-relativistic mean-field models, the relativistic effects on nuclear structures in momentum space are analyzed. Finally, by analogizing the tensor correlations in deuteron and Jastrow-type correlations in nuclear matter, the behaviors and contributions of $ NN $ correlations in $^{56}\text{Fe}$ are further analyzed, which helps clarify the effects of the tensor force on the NMD of heavy nuclei.