Nucleus-nucleus potentials are determined in the framework of double folding model for M3Y-Reid and M3Y- Paris effective nucleon-nucleon （NN） interactions. Both zero-range and finite-range exchange parts of NN inter...Nucleus-nucleus potentials are determined in the framework of double folding model for M3Y-Reid and M3Y- Paris effective nucleon-nucleon （NN） interactions. Both zero-range and finite-range exchange parts of NN interactions are considered in the folding procedure. In this paper the spherical projectile-spherical target system 16O＋^2008Pb is selected for calculating the barrier energies, fusion cross sections and barrier distributions with the density-independent and density-dependent NN interactions on the basis of M3Y-Reid and M3Y Paris NN interactions. The barrier energies become lower for Paris NN interactions in comparison with Reid NN interactions, and also for finite-range exchange part in comparison with zero-range exchange part. The density-dependent NN interactions give similar fusion cross sections and barrier distributions, and the density-independent NN interaction causes the barrier distribution moving to a higher position. However, the density-independent Reid NN interaction with zero-range exchange part gives the lowest fusion cross sections. We find that the calculated fusion cross sections and the barrier distributions are in agreement with the experimental data after renormalization of the nuclear potential due to coupled-channel effect.展开更多
Probing in-medium nucleon-nucleon （NN） cross section σ1/NN（α） in heavy ion collisions has been investigated by means of the isospin-dependent quantum molecular dynamics （IQMD） with the isospin- and momentum-de...Probing in-medium nucleon-nucleon （NN） cross section σ1/NN（α） in heavy ion collisions has been investigated by means of the isospin-dependent quantum molecular dynamics （IQMD） with the isospin- and momentum-dependent interaction （IMDI（T））. It is found that there are the very obvious medium effect and the sensitive isospin-dependence of nuclear stopping R on the in-medium NN cross section α1/NN（α） in the nuclear reactions induced by halo-neutron projectile and the same-mass stable projectile. However, R induced by the neutron-halo projectile is obviously lower than that induced by the corresponding stable projectile. In particular, there is a very obvious dependence of R on the medium effect of σ1/NN（α） in the whole beam energy region for the above two kinds of projectiles. Therefore, the comparison between the results of R＇s in the reactions induced by the neutron-halo projectile and the corresponding same-mass stable projectile is a more favourable probe for extracting the information of σ1/NN（α） because of adding a new judgement.展开更多
Using the most recent phase shift data for pp,nn,and np elastic scattering for different states (l=0,1,...) in the energy range of i MeV to 350 MeV,the charge dependency of the strong nuclear force is investigated.Our...Using the most recent phase shift data for pp,nn,and np elastic scattering for different states (l=0,1,...) in the energy range of i MeV to 350 MeV,the charge dependency of the strong nuclear force is investigated.Our results indicate that although the charge independency holds in most of the energy range,such charge independency is broken in the particular energy range of 120 MeV to 200 MeV for all partial wave states considered here.展开更多
Although often used in molecular dynamics,in this work the Manning-Rosen potential is parameterized to compute the scattering phase shifts for the nucleon-nucleon and the alphanucleon systems by exploiting the standar...Although often used in molecular dynamics,in this work the Manning-Rosen potential is parameterized to compute the scattering phase shifts for the nucleon-nucleon and the alphanucleon systems by exploiting the standard phase function method.We obtain excellent agreement in phase shifts with the more sophisticated calculations up to partial waves l=2.展开更多
We provide a microscopic calculation of neutron-proton and proton-proton cross sections in symmetric nuclear matter at various densities, using the Brueckner Hartree-Fock approximation scheme with the Argonne Va4 pote...We provide a microscopic calculation of neutron-proton and proton-proton cross sections in symmetric nuclear matter at various densities, using the Brueckner Hartree-Fock approximation scheme with the Argonne Va4 potential including the contribution of microscopic three-body force. We investigate separately the effects of three-body force on the effective mass and on the scattering amplitude. In the present calculation, the rearrangement contribution of three-body force is considered, which will reduce the neutron and proton effective mass, and depress the amplitude of cross section. The effect of three body force is shown to be repulsive, especially in high densities and large momenta, which will suppress the cross section markedly.展开更多
A formula is derived for the central nucleon-nucleon potential, based on an analysis of the physical origin of the nucleon-nucleon attraction by pion exchange. The decrease of the dynamical mass of the interaction fie...A formula is derived for the central nucleon-nucleon potential, based on an analysis of the physical origin of the nucleon-nucleon attraction by pion exchange. The decrease of the dynamical mass of the interaction field, exchanged pion in this case, is the principal mechanism responsible for the nuclear attraction in a similar way that the decrease of the kinetic energy of the exchange electron in the diatomic molecule is directly responsible for the covalent molecular attraction. The minimum value of this central nucleon-nucleon potential and the position of the minimum are similar with the values reported in literature for a potential calculated by lattice QCD, which shares the features of the phenomenological nucleon-nucleon potentials. The Schrodinger equation with this central nucleon-nucleon potential was solved numerically for different values of the pion mass. The binding energy increases with the decrease of the pion mass. For masses higher than the real pion mass the nucleon-nucleon system is unbound. We discuss on the two pion exchange and hard core repulsion. The minimum value of the potential for two pion exchange is comparable with the minimum value of the CD Bonn potential. For a hard core radius of 0.5 fm the binding energy is equal to the deuteron binding energy.展开更多
In the hydrogen molecular ion, the kinetic energy lowering of the electron is associated with its delocalization due to electron exchange between the two protons of the molecule. This decrease in the kinetic energy of...In the hydrogen molecular ion, the kinetic energy lowering of the electron is associated with its delocalization due to electron exchange between the two protons of the molecule. This decrease in the kinetic energy of the exchanged electron in the hydrogen molecular ion and the decrease in the dynamical mass of the two exchanged pions in the nucleon-nucleon interaction are at the origin of the attraction mechanism in the molecular covalent bonding and in the nuclear interaction. Based on this unitary approach of the attraction mechanism, the formulas of molecular potential and central nucleon-nucleon potential were derived. The decrease in the mass of the exchanged pions in the nucleon-nucleon bound state, actually means the decrease in the mass of the nucleons. This nucleon mass decrease could be a manifestation of the partial chiral symmetry restoration in nuclear matter.展开更多
In nuclear ab initio calculations,nucleon-nucleon interactions are softened via renormalization in order to improve the convergence of calculations.The high-momentum and high-excitation properties of nuclei are not we...In nuclear ab initio calculations,nucleon-nucleon interactions are softened via renormalization in order to improve the convergence of calculations.The high-momentum and high-excitation properties of nuclei are not well investigated quantitatively with softened interactions to identify where they may lose predictive power though the low energy observables remain nearly unchanged after the renormalization.In this work,we study nuclear high-mo-mentum properties and high-excitation properties with realistic interactions taking the simplest nucleus,i.e.,deuter-on,as an example.In particular,we study the nucleon momentum distribution and photoabsorption cross section with a chiral effective field theory interaction at N^(3)LO and two softened interactions based on it,i.e.,N^(3)LO-SRG and Daejeon16 interactions.We find that the nucleon momentum distributions of the deuteron calculated with these two soft interactions are significantly suppressed at momenta above 200 MeV in comparison to those calculated with the N^(3)LO chiral interaction.The photoabsorption cross sections of the deuteron calculated with these three interac-tions are overall in agreement with the experimental data.The N^(3)LO-SRG results deviate slightly from the experi-mental data above about 15 MeV due to the renormalization process.The Daejeon16 results deviate more apparently from the experimental data above the peak value compared to the N^(3)LO-SRG results due to the phase equivalent transformations.展开更多
The effects of nucleon-nucleon short-range correlations leading to the high-momentum tail(HMT)in the nucleon momentum distribution are studied using the iso spin-and momentum-dependent Lanzhou quantum molecular dynami...The effects of nucleon-nucleon short-range correlations leading to the high-momentum tail(HMT)in the nucleon momentum distribution are studied using the iso spin-and momentum-dependent Lanzhou quantum molecular dynamics(LQMD)transport model.Based on the transport model,we study the effects of the HMT of the nucleon momentum distribution on initialization in isotopic nuclear reactions at a beam energy of 120 MeV/u.The single and double ratios of gas-phase neutron and proton spectra are analyzed and compared with experimental data in central ^(112)Sn+^(112)Sn and^(124)Sn+^(124)Sn collisions.The HMT affects the single ratios but not the double ratios,which can be employed to study other iso spin effects more effectively.The ratio of triton to 3 He of light clusters contained in the gas-phase nucleons is also influenced by the HMT.Combining the QMD transport model that can describe multifragmentation and the production of fragments in intermediate-energy heavy-ion collisions,we study the short-range correlation effect on fragment generation.We find that the iso spin-dependent HMT significantly affects the fragment multiplicity distribution and average neutron-to-proton ratio of produced isobars.展开更多
In recent years,neutrino-nucleus scattering has been extensively researched to investigate nuclear structures and interactions between neutrinos and nucleons.In this study,a charged-current quasielastic(CCQE)neutrino-...In recent years,neutrino-nucleus scattering has been extensively researched to investigate nuclear structures and interactions between neutrinos and nucleons.In this study,a charged-current quasielastic(CCQE)neutrino-nucleus scattering model is developed to explore the nuclear mean-field dynamics and short-range correlation effects.In this model,the effect of the nuclear structure is depicted using the scaling function f(ψ),whereas the neutrino-nucleon interaction is represented by the elementary weak cross sectionσ_(0).The results indicate that the double-differential cross section of the scattered muon is influenced by the energy E and mo mentum p of the nucleon in the nuclei,and the total cross section depends primarily on the incident neutrino energy E_(ν).Furthermore,incorporating short-range correlations results in the flux-integrated differential cross sections in the high-T_(μ)region producing larger values,a longer tail,and achieving better experimental consistency.It eventually elucidates the physical relationship between the neutrino-nucleus scattering cross section and variation in the incident neutrino energy.This paper shares insights for the research on nucleon dynamics and presents detailed investigations of the neutrino-nucleus scattering mechanism.展开更多
Within the framework of the improved quantum molecular dynamics model, the medium modifications of the free nucleon-nucleon elastic cross-sections are investigated. By using various in-medium nucleon-nucleon elastic c...Within the framework of the improved quantum molecular dynamics model, the medium modifications of the free nucleon-nucleon elastic cross-sections are investigated. By using various in-medium nucleon-nucleon elastic cross-sections in the model, the nucleon induced reactions on various targets are simulated, and the excitation functions of reaction cross-sections in the energy range from 25 MeV to 1 GeV are calculated. By comparing the calculations with the experimental data, the isospin, density, and momentum dependence of the medium correction factors of free nucleon-nucleon elastic cross-sections are determined.展开更多
Nucleon momentum distribution(NMD), particularly its high-momentum components, is essential for understanding the nucleonnucleon(NN) correlations in nuclei. Herein, we develop the studies of NMD of 56Fe from the axial...Nucleon momentum distribution(NMD), particularly its high-momentum components, is essential for understanding the nucleonnucleon(NN) correlations in nuclei. Herein, we develop the studies of NMD of 56Fe 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 < kF, the effects of deformation on the NMD of the RMF model are investigated using the total and single-particle NMDs. For the region k > kF, 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 56Fe are further analyzed, which helps clarify the effects of the tensor force on the NMD of heavy nuclei.展开更多
Motivated by the successes of relativistic theories in studies of atomic/molecular and nuclear systems and the need for a relativistic chiral force in relativistic nuclear structure studies, we explore a new relativis...Motivated by the successes of relativistic theories in studies of atomic/molecular and nuclear systems and the need for a relativistic chiral force in relativistic nuclear structure studies, we explore a new relativistic scheme to construct the nucleon-nucleon interaction in the framework of covariant chiral effective field theory. The chiral interaction is formulated up to leading order with covariant power counting and a Lorentz invariant chiral Lagrangian.We find that the relativistic scheme induces all six spin operators needed to describe the nuclear force. A detailed investigation of the partial wave potentials shows a better description of the;S——0 and;P;phase shifts than the leading order Weinberg approach, and similar to that of the next-to-leading order Weinberg approach. For the other partial waves with angular momenta J≥1, the relativistic results are almost the same as their leading order non-relativistic counterparts.展开更多
The nucleon-nucleon interaction is investigated by using the improved quantum molecular dynamic （ImQMD） model with three sets of parameters IQ1, IQ2 and IQ3, in which the corresponding incompressibility coefficients...The nucleon-nucleon interaction is investigated by using the improved quantum molecular dynamic （ImQMD） model with three sets of parameters IQ1, IQ2 and IQ3, in which the corresponding incompressibility coefficients of nuclear matter are different. The charge distributions of fragments are calculated for various reaction systems at different incident energies. The parameters strongly affect the charge distributions and the fragment multiplicity spectrum below the threshold energy of nuclear multifragmentation. The fragment multiplicity spectrum for 238U＋197Au at 15 A MeV and the charge distributions for 129Xe＋12~Sn at 32 and 45 A MeV, and 197Au＋197Au at 35 A MeV are reproduced by the ImQMD model with the set of parameter IQ3. It is found that： 1） The charge distribution of the fragments and the fragment multiplicity spectrum are good observables for testing the model and the parameters. 2） The Fermi energy region is a sensitive energy region for studying nucleon-nucleon interaction.展开更多
Based on a theory of extra dimensional confinement of quantum particles [E. R. Hedin, Physics Essays, 2012, 25（2）： 177], a simple model of a nucleon nucleon （NN） central potential is derived which quantitatively ...Based on a theory of extra dimensional confinement of quantum particles [E. R. Hedin, Physics Essays, 2012, 25（2）： 177], a simple model of a nucleon nucleon （NN） central potential is derived which quantitatively reproduces tile radial profile of other models, without adjusting any free pa- rameters. It is postulated that a higher-dimensional simple harmonic oscillator confining potential localizes particles into three-dimensional （3D） space, but allows for an ewmescent penetration of the particles into two higtmr spatial dimensions. Producing an effect identical with the relativistic quan- tum phenolnenon of zitterbewegung, the higher-dimensional oscillations of amplitude h（mc） call be alternatively viewed as a localized curvature of 3D space back and forth into the higher dimensions. The overall spatial curvature is proportional to the particle＇s extra-dimensional ground state wave function in tile higher-dimensional harmonic confining potential well. Minimizing the overlapping curvature （proportional to the energy） of two particles in proximity to each other, subject to the constraint that for the two particles to occupy the same spatial location one of them must be excited into the 1st excited state of the harmonic potential well, gives the desired NN potential. Specifying only the imcleon masses, the resulting potential well and repulsive core reproduces the radial profile of several published NN central potential models. In addition, the predicted height of the repulsive core, when used to estimate the maximum neutron star mass, matches well with the best estimates from relativistic theory incorporating standard nuclear matter equations of state. Nucleon spin, Coulomb interactions, and internal nucleon structure are not considered in the theory as presented in this article.展开更多
In this work,we study the renormalization group invariance of the recently proposed covariant power counting in the case of nucleon-nucleon scattering[Chin.Phys.C 42(2018)014103]at leading order.We show that unlike th...In this work,we study the renormalization group invariance of the recently proposed covariant power counting in the case of nucleon-nucleon scattering[Chin.Phys.C 42(2018)014103]at leading order.We show that unlike the Weinberg scheme,renormalizaion group invariance is satisfied in the^(3)P0 channel.Another interesting feature is that the^(1)S0 and^(3)P1 channels are correlated.Fixing the relevant low energy constants by ftting to the^(1)S0 phase shiftsat T_(lab)=10 and 25 MeV with cutoff values∧=400-650 MeV,one can describe the 3 P1 phase shifts relatively well.In the limit of∧→∞,the^(1)S0 phase shifts become cutoff-independent,whereas the 3P1 phase shifts do not.This is consistent with the Wigner bound and previous observations that the 3P1 channel is best treated perturbatively.As for the^(2)P1 and^(3)S1-^(3)D1 channels,renormalization group invariance is satisfied.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 60572177)
文摘Nucleus-nucleus potentials are determined in the framework of double folding model for M3Y-Reid and M3Y- Paris effective nucleon-nucleon （NN） interactions. Both zero-range and finite-range exchange parts of NN interactions are considered in the folding procedure. In this paper the spherical projectile-spherical target system 16O＋^2008Pb is selected for calculating the barrier energies, fusion cross sections and barrier distributions with the density-independent and density-dependent NN interactions on the basis of M3Y-Reid and M3Y Paris NN interactions. The barrier energies become lower for Paris NN interactions in comparison with Reid NN interactions, and also for finite-range exchange part in comparison with zero-range exchange part. The density-dependent NN interactions give similar fusion cross sections and barrier distributions, and the density-independent NN interaction causes the barrier distribution moving to a higher position. However, the density-independent Reid NN interaction with zero-range exchange part gives the lowest fusion cross sections. We find that the calculated fusion cross sections and the barrier distributions are in agreement with the experimental data after renormalization of the nuclear potential due to coupled-channel effect.
基金Project supported by the State Key Development Program for Basic Research of China （Grant No G2000077400）, the Major Program of the National Natural Science Foundation of China （Grant Nos 10435080 and 105350101）, the National Natural Science Foundation of China （Grant Nos 10447006 and 10575075）, the CAS Knowledge Innovation Project Program （Grant No KJCX2-SW-N02）.
文摘Probing in-medium nucleon-nucleon （NN） cross section σ1/NN（α） in heavy ion collisions has been investigated by means of the isospin-dependent quantum molecular dynamics （IQMD） with the isospin- and momentum-dependent interaction （IMDI（T））. It is found that there are the very obvious medium effect and the sensitive isospin-dependence of nuclear stopping R on the in-medium NN cross section α1/NN（α） in the nuclear reactions induced by halo-neutron projectile and the same-mass stable projectile. However, R induced by the neutron-halo projectile is obviously lower than that induced by the corresponding stable projectile. In particular, there is a very obvious dependence of R on the medium effect of σ1/NN（α） in the whole beam energy region for the above two kinds of projectiles. Therefore, the comparison between the results of R＇s in the reactions induced by the neutron-halo projectile and the corresponding same-mass stable projectile is a more favourable probe for extracting the information of σ1/NN（α） because of adding a new judgement.
文摘Using the most recent phase shift data for pp,nn,and np elastic scattering for different states (l=0,1,...) in the energy range of i MeV to 350 MeV,the charge dependency of the strong nuclear force is investigated.Our results indicate that although the charge independency holds in most of the energy range,such charge independency is broken in the particular energy range of 120 MeV to 200 MeV for all partial wave states considered here.
文摘Although often used in molecular dynamics,in this work the Manning-Rosen potential is parameterized to compute the scattering phase shifts for the nucleon-nucleon and the alphanucleon systems by exploiting the standard phase function method.We obtain excellent agreement in phase shifts with the more sophisticated calculations up to partial waves l=2.
基金supported by the Asia-Link project(CN/ASIA-LINK/008(94791))of the European Commissionin part by National Natural Science Foundation of China under Grant Nos.10775061,10505016,10575119,and 10175074+1 种基金the Knowledge Innovative Project of CAS under Grant No.KJCX3-SYW-N2the Major Prophase Research Project of Fundamental Research of the Ministry of Science and Technology of China under Grant No.2007CB815004
文摘We provide a microscopic calculation of neutron-proton and proton-proton cross sections in symmetric nuclear matter at various densities, using the Brueckner Hartree-Fock approximation scheme with the Argonne Va4 potential including the contribution of microscopic three-body force. We investigate separately the effects of three-body force on the effective mass and on the scattering amplitude. In the present calculation, the rearrangement contribution of three-body force is considered, which will reduce the neutron and proton effective mass, and depress the amplitude of cross section. The effect of three body force is shown to be repulsive, especially in high densities and large momenta, which will suppress the cross section markedly.
文摘A formula is derived for the central nucleon-nucleon potential, based on an analysis of the physical origin of the nucleon-nucleon attraction by pion exchange. The decrease of the dynamical mass of the interaction field, exchanged pion in this case, is the principal mechanism responsible for the nuclear attraction in a similar way that the decrease of the kinetic energy of the exchange electron in the diatomic molecule is directly responsible for the covalent molecular attraction. The minimum value of this central nucleon-nucleon potential and the position of the minimum are similar with the values reported in literature for a potential calculated by lattice QCD, which shares the features of the phenomenological nucleon-nucleon potentials. The Schrodinger equation with this central nucleon-nucleon potential was solved numerically for different values of the pion mass. The binding energy increases with the decrease of the pion mass. For masses higher than the real pion mass the nucleon-nucleon system is unbound. We discuss on the two pion exchange and hard core repulsion. The minimum value of the potential for two pion exchange is comparable with the minimum value of the CD Bonn potential. For a hard core radius of 0.5 fm the binding energy is equal to the deuteron binding energy.
文摘In the hydrogen molecular ion, the kinetic energy lowering of the electron is associated with its delocalization due to electron exchange between the two protons of the molecule. This decrease in the kinetic energy of the exchanged electron in the hydrogen molecular ion and the decrease in the dynamical mass of the two exchanged pions in the nucleon-nucleon interaction are at the origin of the attraction mechanism in the molecular covalent bonding and in the nuclear interaction. Based on this unitary approach of the attraction mechanism, the formulas of molecular potential and central nucleon-nucleon potential were derived. The decrease in the mass of the exchanged pions in the nucleon-nucleon bound state, actually means the decrease in the mass of the nucleons. This nucleon mass decrease could be a manifestation of the partial chiral symmetry restoration in nuclear matter.
文摘In nuclear ab initio calculations,nucleon-nucleon interactions are softened via renormalization in order to improve the convergence of calculations.The high-momentum and high-excitation properties of nuclei are not well investigated quantitatively with softened interactions to identify where they may lose predictive power though the low energy observables remain nearly unchanged after the renormalization.In this work,we study nuclear high-mo-mentum properties and high-excitation properties with realistic interactions taking the simplest nucleus,i.e.,deuter-on,as an example.In particular,we study the nucleon momentum distribution and photoabsorption cross section with a chiral effective field theory interaction at N^(3)LO and two softened interactions based on it,i.e.,N^(3)LO-SRG and Daejeon16 interactions.We find that the nucleon momentum distributions of the deuteron calculated with these two soft interactions are significantly suppressed at momenta above 200 MeV in comparison to those calculated with the N^(3)LO chiral interaction.The photoabsorption cross sections of the deuteron calculated with these three interac-tions are overall in agreement with the experimental data.The N^(3)LO-SRG results deviate slightly from the experi-mental data above about 15 MeV due to the renormalization process.The Daejeon16 results deviate more apparently from the experimental data above the peak value compared to the N^(3)LO-SRG results due to the phase equivalent transformations.
基金Supported by the National Natural Science Foundation of China(12305130)China Postdoctoral Science Foundation(2023M731016)+1 种基金Henan Postdoctoral Foundation(HN2022164)the Natural Science Foundation of Henan Province(242300422048)。
文摘The effects of nucleon-nucleon short-range correlations leading to the high-momentum tail(HMT)in the nucleon momentum distribution are studied using the iso spin-and momentum-dependent Lanzhou quantum molecular dynamics(LQMD)transport model.Based on the transport model,we study the effects of the HMT of the nucleon momentum distribution on initialization in isotopic nuclear reactions at a beam energy of 120 MeV/u.The single and double ratios of gas-phase neutron and proton spectra are analyzed and compared with experimental data in central ^(112)Sn+^(112)Sn and^(124)Sn+^(124)Sn collisions.The HMT affects the single ratios but not the double ratios,which can be employed to study other iso spin effects more effectively.The ratio of triton to 3 He of light clusters contained in the gas-phase nucleons is also influenced by the HMT.Combining the QMD transport model that can describe multifragmentation and the production of fragments in intermediate-energy heavy-ion collisions,we study the short-range correlation effect on fragment generation.We find that the iso spin-dependent HMT significantly affects the fragment multiplicity distribution and average neutron-to-proton ratio of produced isobars.
基金supported by the National Natural Science Foundation of China(12475135,12035011)by the Shandong Provincial Natural Science Foundation,China(ZR2020MA096)by the Fundamental Research Funds for the Central Universities(22CX03017A)。
文摘In recent years,neutrino-nucleus scattering has been extensively researched to investigate nuclear structures and interactions between neutrinos and nucleons.In this study,a charged-current quasielastic(CCQE)neutrino-nucleus scattering model is developed to explore the nuclear mean-field dynamics and short-range correlation effects.In this model,the effect of the nuclear structure is depicted using the scaling function f(ψ),whereas the neutrino-nucleon interaction is represented by the elementary weak cross sectionσ_(0).The results indicate that the double-differential cross section of the scattered muon is influenced by the energy E and mo mentum p of the nucleon in the nuclei,and the total cross section depends primarily on the incident neutrino energy E_(ν).Furthermore,incorporating short-range correlations results in the flux-integrated differential cross sections in the high-T_(μ)region producing larger values,a longer tail,and achieving better experimental consistency.It eventually elucidates the physical relationship between the neutrino-nucleus scattering cross section and variation in the incident neutrino energy.This paper shares insights for the research on nucleon dynamics and presents detailed investigations of the neutrino-nucleus scattering mechanism.
基金Supported by Natural Science Foundation of Guangxi Province(2016GXNSFFA380001,2017GXNSFGA198001)Foundation of Guangxi Innovative Team and Distinguished Scholar in Institutions of Higher EducationNational Natural Science Foundation of China(11365004,U1867212)
文摘Within the framework of the improved quantum molecular dynamics model, the medium modifications of the free nucleon-nucleon elastic cross-sections are investigated. By using various in-medium nucleon-nucleon elastic cross-sections in the model, the nucleon induced reactions on various targets are simulated, and the excitation functions of reaction cross-sections in the energy range from 25 MeV to 1 GeV are calculated. By comparing the calculations with the experimental data, the isospin, density, and momentum dependence of the medium correction factors of free nucleon-nucleon elastic cross-sections are determined.
基金the National Natural Science Foundation of China(Grant Nos.11505292,11605105,11822503,11975167,and 12035011)the Shandong Provincial Natural Science Foundation,China(Grant No.ZR2020MA096)+1 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.20CX05013A,and 22120210138)the Graduate Innovative Research Funds of China University of Petroleum(East China)(Grant No.YCX2020104).
文摘Nucleon momentum distribution(NMD), particularly its high-momentum components, is essential for understanding the nucleonnucleon(NN) correlations in nuclei. Herein, we develop the studies of NMD of 56Fe 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 < kF, the effects of deformation on the NMD of the RMF model are investigated using the total and single-particle NMDs. For the region k > kF, 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 56Fe are further analyzed, which helps clarify the effects of the tensor force on the NMD of heavy nuclei.
基金Supported by National Natural Science Foundation of China(11375024,11522539,11335002,11375120)DFG and NSFC through funds provided to the Sino-German CRC 110“Symmetries and the Emergence of Structure in QCD”(NSFC Grant No.11621131001,DFG Grant No.TRR110)+3 种基金the Major State 973 Program of China(2013CB834400)the China Postdoctoral Science Foundation(2016M600845,2017T100008)the Fundamental Research Funds for the Central Universitiesby the DFG cluster of excellence Origin and Structure of the Universe(www.universe-cluster.de)
文摘Motivated by the successes of relativistic theories in studies of atomic/molecular and nuclear systems and the need for a relativistic chiral force in relativistic nuclear structure studies, we explore a new relativistic scheme to construct the nucleon-nucleon interaction in the framework of covariant chiral effective field theory. The chiral interaction is formulated up to leading order with covariant power counting and a Lorentz invariant chiral Lagrangian.We find that the relativistic scheme induces all six spin operators needed to describe the nuclear force. A detailed investigation of the partial wave potentials shows a better description of the;S——0 and;P;phase shifts than the leading order Weinberg approach, and similar to that of the next-to-leading order Weinberg approach. For the other partial waves with angular momenta J≥1, the relativistic results are almost the same as their leading order non-relativistic counterparts.
基金National Natural Science Foundation of China(11005003,10975095,11275052,11005002)Natural Science Foundation of He’nan Educational Committee(2011A140001,2011GGJS-147)Innovation Fund of Undergraduate at Anyang Normal University(ASCX/2012Z28)
文摘The nucleon-nucleon interaction is investigated by using the improved quantum molecular dynamic （ImQMD） model with three sets of parameters IQ1, IQ2 and IQ3, in which the corresponding incompressibility coefficients of nuclear matter are different. The charge distributions of fragments are calculated for various reaction systems at different incident energies. The parameters strongly affect the charge distributions and the fragment multiplicity spectrum below the threshold energy of nuclear multifragmentation. The fragment multiplicity spectrum for 238U＋197Au at 15 A MeV and the charge distributions for 129Xe＋12~Sn at 32 and 45 A MeV, and 197Au＋197Au at 35 A MeV are reproduced by the ImQMD model with the set of parameter IQ3. It is found that： 1） The charge distribution of the fragments and the fragment multiplicity spectrum are good observables for testing the model and the parameters. 2） The Fermi energy region is a sensitive energy region for studying nucleon-nucleon interaction.
文摘Based on a theory of extra dimensional confinement of quantum particles [E. R. Hedin, Physics Essays, 2012, 25（2）： 177], a simple model of a nucleon nucleon （NN） central potential is derived which quantitatively reproduces tile radial profile of other models, without adjusting any free pa- rameters. It is postulated that a higher-dimensional simple harmonic oscillator confining potential localizes particles into three-dimensional （3D） space, but allows for an ewmescent penetration of the particles into two higtmr spatial dimensions. Producing an effect identical with the relativistic quan- tum phenolnenon of zitterbewegung, the higher-dimensional oscillations of amplitude h（mc） call be alternatively viewed as a localized curvature of 3D space back and forth into the higher dimensions. The overall spatial curvature is proportional to the particle＇s extra-dimensional ground state wave function in tile higher-dimensional harmonic confining potential well. Minimizing the overlapping curvature （proportional to the energy） of two particles in proximity to each other, subject to the constraint that for the two particles to occupy the same spatial location one of them must be excited into the 1st excited state of the harmonic potential well, gives the desired NN potential. Specifying only the imcleon masses, the resulting potential well and repulsive core reproduces the radial profile of several published NN central potential models. In addition, the predicted height of the repulsive core, when used to estimate the maximum neutron star mass, matches well with the best estimates from relativistic theory incorporating standard nuclear matter equations of state. Nucleon spin, Coulomb interactions, and internal nucleon structure are not considered in the theory as presented in this article.
基金the National Natural Science Foundation of China(11735003,11975041,11775148,11961141004)。
文摘In this work,we study the renormalization group invariance of the recently proposed covariant power counting in the case of nucleon-nucleon scattering[Chin.Phys.C 42(2018)014103]at leading order.We show that unlike the Weinberg scheme,renormalizaion group invariance is satisfied in the^(3)P0 channel.Another interesting feature is that the^(1)S0 and^(3)P1 channels are correlated.Fixing the relevant low energy constants by ftting to the^(1)S0 phase shiftsat T_(lab)=10 and 25 MeV with cutoff values∧=400-650 MeV,one can describe the 3 P1 phase shifts relatively well.In the limit of∧→∞,the^(1)S0 phase shifts become cutoff-independent,whereas the 3P1 phase shifts do not.This is consistent with the Wigner bound and previous observations that the 3P1 channel is best treated perturbatively.As for the^(2)P1 and^(3)S1-^(3)D1 channels,renormalization group invariance is satisfied.
