Nucleon momentum distribution of 56 Fe from the axially deformed relativistic mean-field model with nucleon-nucleon correlations

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 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 basing on deuteron and nuclear matter. For the region k < k 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 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 Fe are further analyzed, which helps clarify the effects of the tensor force on the NMD of heavy nuclei.