Research On The Density And Momentum Profile Of Atomic Nuclei

We systematically study the density distribution of atomic nuclei by combining the traditional methods of studying the nuclear structure and the current hot deep learning theory.In this process,a Skyrme-Hartree-Fock(SHF)+BCS model based on density functional theory describing finite nuclei is used to calculate the target nuclei density profile for training deep neural networks.There is a turning point in the process of machine learning that illustrates the transition from a Fermi-like distribution to a realistic Skyrme distribution.It is demonstrated that only about 10%of the nuclei(300-400)are sufficient to describe the nucleon density profile of the overall experimentally discovered nuclide map region,with an average error in the center of less than 2%with respect to the saturation density.Comparing the approach proposed by Bogoliubov to deal with pair correlations and different Skyrme nuclear forces,the neural network yields similar conclusions,suggesting that this approach is general and does not depend on a specific physical model.For the momentum distribution,we use the coordinate space wave function derived from the SHF model to obtain the momentum space wave function of each shell using the Hankel transform(Wigner transform)of the basis vector,and then obtain the momentum distribution.In addition,the momentum distribution of nuclear matter is studied in this paper,and the Brueckner-Hartree-Fock(BHF)model based on the spectral function approach is used to calculate the momentum distribution under different asymmetries and densities.The scalar nature of the momentum distribution under this method is also investigated,and finally a form of momentum distribution is given to describe the density and asymmetry dependence uniformly.In addition to the study of density and momentum distribution from nuclear struc-ture,the effects due to relevant nuclear structure on probes produced by the heavy-ion collision are also investigated using the Isospin-dependent Boltzmann-Uehling-Uhlenbeck(IBUU)transport model.These structural effects are carried out in two ways.On the one hand,different model frameworks-SHF and Shell-Model-were used to generate the density distribution of S and C1 isotope chains.For the Shell-Model,the nucleon cores are usually frozen,so the valence nucleon distribution from the Shell-Model plus the density distribution of ~16O is compared with the mean-field model.Theoretical and experimental requirements for the length of the harmonic os-cillator basis vector of the valence nucleon are different for bHO=2.5 fm and bHO=2.0 fm.For the theoretical case,there is a significant difference in the ? meson yield after the collision;while for the experimental one,there is a significant difference in the double ?~-/?~+ ratio.This study illustrates the collision effect of mixed configurations On the other hand,in the 197Au+197Au reaction with an incident energy of 400 MeV per nucleon,the effect of differences in the high momentum tails(HMTs)of the nucleon momentum distribution in the colliding nuclei on some isospin-sensitive observables is investigated.It is found that the nucleon transverse and elliptic flows,the free n/p ratio at low momenta are all less sensitive to the specific form of the HMT,while the free neutron to proton ratio at high momenta and the yields of ?~-and ?~+ as well as the ?~-/?~+ ratio around the Coulomb peak are sensitive to the specific form of the HMT.In fact,this study combined with the experiment has far-reaching implications for the short-range correlation of nuclear matter or heavy nuclei.