This paper shows a didactic model (PGM), and not only, but representative of the Hadrons described in the Standard Model (SM). In this model, particles are represented by structures corresponding to geometric shapes o...This paper shows a didactic model (PGM), and not only, but representative of the Hadrons described in the Standard Model (SM). In this model, particles are represented by structures corresponding to geometric shapes of coupled quantum oscillators (IQuO). By the properties of IQuO one can define the electric charge and that of color of quarks. Showing the “aurea” (golden) triangular shape of all quarks, we manage to represent the geometric combinations of the nucleons, light mesons, and K-mesons. By the geometric shape of W-bosons, we represent the weak decay of pions and charged Kaons and neutral, highlighting in geometric terms the possibilities of decay in two and three pions of neutral Kaon and the transition to anti-Kaon. In conclusion, from this didactic representation, an in-depth and exhaustive phenomenology of hadrons emerges, which even manages to resolve some problematic aspects of the SM.展开更多
In this paper we consider nucleons as tori, rotating with a constant angular velocity around the straight line passing through their mass centre (geometric centre) and perpendicular to their plane of rotation. We theo...In this paper we consider nucleons as tori, rotating with a constant angular velocity around the straight line passing through their mass centre (geometric centre) and perpendicular to their plane of rotation. We theoretically determine the corresponding potential energy and the force of interaction between pairs of nucleons, using our precise analytical formulas for the electrostatic interaction between two spheres with arbitrary radii and charges, which we derive using experimentally obtained results for the radii and the masses of the nucleons. From the values for binding energy found through our method, it follows that nuclear forces are electromagnetic in nature. In terms of magnitude of the force of interaction between proton and neutron, we obtain that Coulomb's forces are short-range. Our toroid model explains the experimental results not only for binding energy, but also for the radius, magnetic moment and the spin of the nuclei of atoms.展开更多
A nuclear structure model of “ring plus extra nucleon” is proposed. For nuclei larger than 4He, protons (P) and neutrons (N) are basically bound alternatively to form a ZP + ZN ring. The ring folds with a “bond an...A nuclear structure model of “ring plus extra nucleon” is proposed. For nuclei larger than 4He, protons (P) and neutrons (N) are basically bound alternatively to form a ZP + ZN ring. The ring folds with a “bond angle” of 90° for every 3 continuous nucleons to make the nucleons packed densely. Extra N(‘s) can bind to ring-P with the same “bond angle” and “bond distance”. When 2 or more P’s are geometrically available, the extra N tends to be stable. Extra P can bind with ring N in a similar way when the ratio of N/P < 1 although the binding is weaker than that of extra N. Even-Z rings, as well as normal even-even nuclei, always have superimposed gravity centers of P and N;while for odd-Z rings, as well as all odd-A (A: number of nucleon) nuclei, the centers of P and N must be eccentric. The eccentricity results in a depression of binding energy (EB) and therefore odd and even Z dependent zigzag features of EB/A. This can be well explained by the shift of eccentricity by extra nucleons. Symmetrical center may present in even-Z rings and normal even-even nuclei. While for odd-Z ring, only antisymmetric center (every P can find an N through the center and vice versa) is possible. Based on this model, a pair of mirror nuclei, PX+nNX and PXNX+n, should be equivalent in packing structure just like black-white photo and the negative film. Therefore, an identical spin and parity was confirmed for any pair. In addition, the EB/A difference of mirror nuclei pair is nearly a constant of 0.184n MeV. Many other facts can also be easily understood from this model, such as the neutron halo, the unusual stability sequence of 9Be, 7Be and 8Be and so on.展开更多
Study of nucleons charge radii and electromagnetic form factors are expected to provide valuable information about the distribution of electric charge within the fundamental particles in nucleon’s inner structure. In...Study of nucleons charge radii and electromagnetic form factors are expected to provide valuable information about the distribution of electric charge within the fundamental particles in nucleon’s inner structure. In the recent years, dramatic progress has been made in the understanding of the nucleon structure and the precision of its partonic content, due to the vast theoretical progress, and the availability of new high precision measurements. Here in this article, we present a simple model for the charge structure of the nucleons and the most available sets of the structure functions to calculate the mean square charge radius N2> for both protons and neutrons. Our results are consistent with the modern understanding of the nucleons as well as recent experimental data. We discuss the origin of the sign rN2> for both proton and neutron.展开更多
In this paper,we propose a map that connects nucleons bound in nuclei and Ising spins in the Ising model.This proposal is based on the fact that the description of states of nucleons and Ising spins could share the sa...In this paper,we propose a map that connects nucleons bound in nuclei and Ising spins in the Ising model.This proposal is based on the fact that the description of states of nucleons and Ising spins could share the same type of observables.We present a nuclear model corresponding to an explicit modified Ising model and qualitatively confirm the correctness of this map with a simulation on a two-dimensional square lattice.This map can help us understand the profound connections between different physical systems.展开更多
Directed flow(v_(1))of the hypernuclei ^(3)_(Λ)H and ^(4)_(Λ)H have been observed in mid-central Au+Au collisions at√^(s)NN=3 GeV at RHIC.This measurement opens up a new possibility for studying hyperon–nucleon(Y...Directed flow(v_(1))of the hypernuclei ^(3)_(Λ)H and ^(4)_(Λ)H have been observed in mid-central Au+Au collisions at√^(s)NN=3 GeV at RHIC.This measurement opens up a new possibility for studying hyperon–nucleon(Y–N)interaction under finite pressure.In addition,multi-strangeness hypernuclei provide a venue to probe hyperon–nucleon–nucleon(Y–N–N)and even hyperon–hyperon–nucleon(Y–Y–N)interactions.Hypernuclei are important for making connection between nuclear collisions and the equation of state which governs the inner structure of compact stars.展开更多
Lambda polarization can be measured through its self-analyzing weak decay, making it an ideal candidate for studying spin effects in high-energy scattering. In lepton-nucleon deep inelastic scattering(DIS), Lambda pol...Lambda polarization can be measured through its self-analyzing weak decay, making it an ideal candidate for studying spin effects in high-energy scattering. In lepton-nucleon deep inelastic scattering(DIS), Lambda polarization measurements can probe polarized parton distribution functions(PDFs) and polarized fragmentation functions(FFs). One of the most promising facilities for high-energy nuclear physics research is the proposed Electron-ion collider in China(EicC). As a next-generation facility, EicC is set to advance our understanding of nuclear physics to new heights. In this article, we study the Lambda production in electron-proton collisions at the EicC energy, in particular the reconstruction of Lambda based on the performance of the designed EicC detector. In addition, taking spontaneous transverse polarization as an example, we provide a theoretical prediction with a statistical projection based on one month of EicC data, offering valuable insights into future research prospects.展开更多
Based on a model of fermions which implies a model of photons, a model of the neutron is constructed by merging two photons of equal energy propagating in opposite directions. The fermion model is outlined, and the me...Based on a model of fermions which implies a model of photons, a model of the neutron is constructed by merging two photons of equal energy propagating in opposite directions. The fermion model is outlined, and the merging of two photons is described in detail. The radius of the neutron obtained in this way is Rn = 0.84008… fm. This value is four times the reduced Compton wavelength of the neutron. Assuming the same model for the proton, one obtains a value of Rp = 0.84123… fm, which agrees with the most recent experimental value for the charge radius of the proton within the given limits of error. The neutral charge of the neutron is reproduced, and the positive charge of the proton follows within the model, if the proton is formed via the anti-neutron by losing one electron. S = ±ħ/2, and zero dipole moment, is also reproduced for proton and neutron. Further, a value of the magnetic moment of the neutron of μ= &minus2.00μN (μN: nuclear magnetic moment), and of the proton of μ = 2.666… μN is predicted. The deviation by ca. 5% from the recommended respective values of (&minus1.9130μn), and (2.793μn) is ascribed to the (g-2)-anomaly. Finally, the relation of the model with the established description of the nucleons in terms of three quarks bound by gluons is shortly discussed.展开更多
Nucleon-nucleon (NN) correlations and their isospin dependence in asymmetric nuclear matter are of great nterest since they are closely related to the structure of neutron-rich nuclei[1], particle production in heavy-...Nucleon-nucleon (NN) correlations and their isospin dependence in asymmetric nuclear matter are of great nterest since they are closely related to the structure of neutron-rich nuclei[1], particle production in heavy-ion ollisions[2], and neutron-star physics[3]. The many-body correlations among nucleons can be directly reflected in the neutron and proton spectral functions[4], and the latter may play an important role in understanding the nature f the NN correlations, especially the short-range and tensor correlations in asymmetric nuclear matter.展开更多
The quark and gluon distributions in nuclei are investigated by a parton model,where the common partons of several nucleons and the non-nucleonic components are considered.The comparisons of this model with the data f...The quark and gluon distributions in nuclei are investigated by a parton model,where the common partons of several nucleons and the non-nucleonic components are considered.The comparisons of this model with the data for F_(2)^(A1)(x)/F_(2)^(A2)(x)and the recent data for G_(Sn)(x)/G_(C)(x)are also present.展开更多
We study the interaction forces in atomic nuclei based on our expressions for the electrostatic interaction between spheres of arbitrary radii and charges. We prove that at small distances the proton-neutron electrost...We study the interaction forces in atomic nuclei based on our expressions for the electrostatic interaction between spheres of arbitrary radii and charges. We prove that at small distances the proton-neutron electrostatic attraction forces are short-range-acting and the proton-proton electrostatic repulsion forces are long-range-acting. We obtain that these forces are commensurate with the nuclear forces. The protonneutron electrostatic attraction forces and the proton-proton electrostatic repulsion forces at the same distance between nucleons differ in absolute value by about an order of magnitude. It follows that based on electromagnetic interactions the neutrons are the binding building blocks in nuclear structures.展开更多
The relativistic neutrino emissivity of the nucleonic direct URCA processes in neutron star matter is investigated within the relativistic Hartree-Fock approximation. We particularly study the influences of the tensor...The relativistic neutrino emissivity of the nucleonic direct URCA processes in neutron star matter is investigated within the relativistic Hartree-Fock approximation. We particularly study the influences of the tensor couplings of vector mesons ω and ρ on the nucleonic direct URCA processes. It is found that the inclusion of the tensor couplings of vector mesons w and p can slightly increase the maximum mass of neutron stars. In addition, the results indicate that the tensor couplings of vector mesons ω and ρ lead to obvious enhancement of the total neutrino emissivity for the nucleonic direct URCA processes, which must accelerate the cooling rate of the non- superfluid neutron star matter. However, when considering only the tensor coupling of vector meson ρ, the neutrino emissivity for the nucleonic direct URCA processes slightly declines at low densities and significantly increases at high densities. That is, the tensor coupling of vector meson ρ leads to the slow cooling rate of a low-mass neutron star and rapid cooling rate of a massive neutron star.展开更多
Within the framework of a semiclassical Boltzmann-Uehling-Uhlenbeck (BUU) transport model, the high mo- mentum tail (HMT) effects of nucleon momentum distribution in the nucleus on the nucleon collective flows are...Within the framework of a semiclassical Boltzmann-Uehling-Uhlenbeck (BUU) transport model, the high mo- mentum tail (HMT) effects of nucleon momentum distribution in the nucleus on the nucleon collective flows are studied in semieentral Au+Au collisions. The HMT due to the isospin-dependent short-range correlations causes a smaller value of the collective flows. We find that the HMT effects on the nucleon collective flows are remarkable at beam energy of 300 MeV/nucleon and become weak as the incident beam energy increases. The results indicate that for the collective flow studies at intermediate energies, the HMT of nucleon momentum distribution in nucleus should be taken into account in transport models.展开更多
With the Munczek-Nemirovsky model of the effective gluon propagator in the global colour model, we study the radially excited solitons in which one quark is excited and the other two are at the ground state. The obtai...With the Munczek-Nemirovsky model of the effective gluon propagator in the global colour model, we study the radially excited solitons in which one quark is excited and the other two are at the ground state. The obtained masses of the two radial excitations are comparable with the experimental data.展开更多
By using the chiral quark model and the quark delocalization colour screening model,the phase shifts of nucleonnucleon scattering for high partial waves are studied.The results of both the models are almost equivalent...By using the chiral quark model and the quark delocalization colour screening model,the phase shifts of nucleonnucleon scattering for high partial waves are studied.The results of both the models are almost equivalent.None of the quark models used have found any resonance-like structure in^(3)F_(2),^(3)F_(3),^(3)F_(4)and^(3)H_(4)partial waves.展开更多
A set of new global phenomenological optical model potential parameters has been obtained in the mass range of target nuclei 220≤A≤260 with incident energies below 300 MeV, by simultaneously fitting the experimental...A set of new global phenomenological optical model potential parameters has been obtained in the mass range of target nuclei 220≤A≤260 with incident energies below 300 MeV, by simultaneously fitting the experimental data of 232Th and 23Su, and these potential parameters are analyzed and used to calculate the reaction cross sections, energy spectra and double differ- ential cross sections for p+232Th reaction. Comparison of calculated results using these potential parameters with available experimental data shows that the present form of global optical model potential could reproduce experimental data for both the neutron and the proton.展开更多
The experimental data of the isotopic distribution for projectile-like fragments are presented for the 17,18N + 197Au reaction at 33 MeV/u. The width of the isotopic distributions for lSN projectile is significantly ...The experimental data of the isotopic distribution for projectile-like fragments are presented for the 17,18N + 197Au reaction at 33 MeV/u. The width of the isotopic distributions for lSN projectile is significantly broader than that for 17N projectile, and the average N/Z ratio of the former shifts to higher neutron number side. As long as the realistic nucleon density distribution is used, the isotopic distribution for fragments is reproduced by the simple abrasion-ablation model calculation, which thus provides an independent way to determine the surface distribution of the nuclear matter density for neutron-rich nuclei.展开更多
Using a new set of nucleon coupling constants CZll the properties of a proto neutron star are examined within the framework of the relativistic mean-field theory for the baryon octet system. It is found that the relat...Using a new set of nucleon coupling constants CZll the properties of a proto neutron star are examined within the framework of the relativistic mean-field theory for the baryon octet system. It is found that the relative number density of A,≡ , and ≡0 for CZll are all smaller than those for GL97 and for both CZ11 and GL97, ∑-∑0 and ∑+ do not appear. It is also found that the pressure and the maximum mass for CZll are all smaller than those for GL97. The maximum mass for CZ11 decreases by approximately 9 percent compared with that for GL97.展开更多
The binding energies of all hydrogen isotopes have been calculated successfully for the first time in a previous paper [J Fusion Energy, 30 (2011) 377], using only the electric and magnetic Coulomb’s laws, without us...The binding energies of all hydrogen isotopes have been calculated successfully for the first time in a previous paper [J Fusion Energy, 30 (2011) 377], using only the electric and magnetic Coulomb’s laws, without using the hypothetical shell model of the nucleus and its mysterious strong force. In this paper, an elementary calculation gives the order of magnitude of the nuclear interaction. The binding energies of the deuteron and the alpha particle are then calculated by taking into account the proton induced electric dipole in the neutron. The large binding energy per nucleon of 4He, as compared to that of 2H, has been explained by a larger electric attraction combined with a lower magnetic repulsion. The binding energies have been calculated without fitting, using only fundamental laws and constants, proving that the nuclear interaction is only electromagnetic.展开更多
We compare the static nucleon properties in the Chiral Perturbation Theory (χPT) and the Linear Sigma Model (LSM). We consider a chiral model for the nucleon which is based on the linear sigma model with scalar-isosc...We compare the static nucleon properties in the Chiral Perturbation Theory (χPT) and the Linear Sigma Model (LSM). We consider a chiral model for the nucleon which is based on the linear sigma model with scalar-isoscalar and scalarisovector mesons coupled to quarks. We have solved the field equations in the mean field approximation for the hedgehog baryon state with different sets of model parameters. A good investigation of some static nucleon properties is obtained by the LSM.展开更多
文摘This paper shows a didactic model (PGM), and not only, but representative of the Hadrons described in the Standard Model (SM). In this model, particles are represented by structures corresponding to geometric shapes of coupled quantum oscillators (IQuO). By the properties of IQuO one can define the electric charge and that of color of quarks. Showing the “aurea” (golden) triangular shape of all quarks, we manage to represent the geometric combinations of the nucleons, light mesons, and K-mesons. By the geometric shape of W-bosons, we represent the weak decay of pions and charged Kaons and neutral, highlighting in geometric terms the possibilities of decay in two and three pions of neutral Kaon and the transition to anti-Kaon. In conclusion, from this didactic representation, an in-depth and exhaustive phenomenology of hadrons emerges, which even manages to resolve some problematic aspects of the SM.
文摘In this paper we consider nucleons as tori, rotating with a constant angular velocity around the straight line passing through their mass centre (geometric centre) and perpendicular to their plane of rotation. We theoretically determine the corresponding potential energy and the force of interaction between pairs of nucleons, using our precise analytical formulas for the electrostatic interaction between two spheres with arbitrary radii and charges, which we derive using experimentally obtained results for the radii and the masses of the nucleons. From the values for binding energy found through our method, it follows that nuclear forces are electromagnetic in nature. In terms of magnitude of the force of interaction between proton and neutron, we obtain that Coulomb's forces are short-range. Our toroid model explains the experimental results not only for binding energy, but also for the radius, magnetic moment and the spin of the nuclei of atoms.
文摘A nuclear structure model of “ring plus extra nucleon” is proposed. For nuclei larger than 4He, protons (P) and neutrons (N) are basically bound alternatively to form a ZP + ZN ring. The ring folds with a “bond angle” of 90° for every 3 continuous nucleons to make the nucleons packed densely. Extra N(‘s) can bind to ring-P with the same “bond angle” and “bond distance”. When 2 or more P’s are geometrically available, the extra N tends to be stable. Extra P can bind with ring N in a similar way when the ratio of N/P < 1 although the binding is weaker than that of extra N. Even-Z rings, as well as normal even-even nuclei, always have superimposed gravity centers of P and N;while for odd-Z rings, as well as all odd-A (A: number of nucleon) nuclei, the centers of P and N must be eccentric. The eccentricity results in a depression of binding energy (EB) and therefore odd and even Z dependent zigzag features of EB/A. This can be well explained by the shift of eccentricity by extra nucleons. Symmetrical center may present in even-Z rings and normal even-even nuclei. While for odd-Z ring, only antisymmetric center (every P can find an N through the center and vice versa) is possible. Based on this model, a pair of mirror nuclei, PX+nNX and PXNX+n, should be equivalent in packing structure just like black-white photo and the negative film. Therefore, an identical spin and parity was confirmed for any pair. In addition, the EB/A difference of mirror nuclei pair is nearly a constant of 0.184n MeV. Many other facts can also be easily understood from this model, such as the neutron halo, the unusual stability sequence of 9Be, 7Be and 8Be and so on.
文摘Study of nucleons charge radii and electromagnetic form factors are expected to provide valuable information about the distribution of electric charge within the fundamental particles in nucleon’s inner structure. In the recent years, dramatic progress has been made in the understanding of the nucleon structure and the precision of its partonic content, due to the vast theoretical progress, and the availability of new high precision measurements. Here in this article, we present a simple model for the charge structure of the nucleons and the most available sets of the structure functions to calculate the mean square charge radius N2> for both protons and neutrons. Our results are consistent with the modern understanding of the nucleons as well as recent experimental data. We discuss the origin of the sign rN2> for both proton and neutron.
基金supported in part by the National Natural Science Foundation of China(12105247)the China Postdoctoral Science Foundation(2021M702957)supported in part by the National Natural Science Foundation of China(12002209)。
文摘In this paper,we propose a map that connects nucleons bound in nuclei and Ising spins in the Ising model.This proposal is based on the fact that the description of states of nucleons and Ising spins could share the same type of observables.We present a nuclear model corresponding to an explicit modified Ising model and qualitatively confirm the correctness of this map with a simulation on a two-dimensional square lattice.This map can help us understand the profound connections between different physical systems.
基金supported by supported in part by the National Natural Science Foundation of China(Nos.11890714,12147101)the Guangdong Major Project of Basic and Applied Basic Research(No.2020B0301030008).
文摘Directed flow(v_(1))of the hypernuclei ^(3)_(Λ)H and ^(4)_(Λ)H have been observed in mid-central Au+Au collisions at√^(s)NN=3 GeV at RHIC.This measurement opens up a new possibility for studying hyperon–nucleon(Y–N)interaction under finite pressure.In addition,multi-strangeness hypernuclei provide a venue to probe hyperon–nucleon–nucleon(Y–N–N)and even hyperon–hyperon–nucleon(Y–Y–N)interactions.Hypernuclei are important for making connection between nuclear collisions and the equation of state which governs the inner structure of compact stars.
基金supported by the National Natural Science Foundation of China (Nos.12275159, 12075140, and 12175117)100 Talents Program of CASShandong Provincial Natural Science Foundation (No. ZFJH202303)。
文摘Lambda polarization can be measured through its self-analyzing weak decay, making it an ideal candidate for studying spin effects in high-energy scattering. In lepton-nucleon deep inelastic scattering(DIS), Lambda polarization measurements can probe polarized parton distribution functions(PDFs) and polarized fragmentation functions(FFs). One of the most promising facilities for high-energy nuclear physics research is the proposed Electron-ion collider in China(EicC). As a next-generation facility, EicC is set to advance our understanding of nuclear physics to new heights. In this article, we study the Lambda production in electron-proton collisions at the EicC energy, in particular the reconstruction of Lambda based on the performance of the designed EicC detector. In addition, taking spontaneous transverse polarization as an example, we provide a theoretical prediction with a statistical projection based on one month of EicC data, offering valuable insights into future research prospects.
文摘Based on a model of fermions which implies a model of photons, a model of the neutron is constructed by merging two photons of equal energy propagating in opposite directions. The fermion model is outlined, and the merging of two photons is described in detail. The radius of the neutron obtained in this way is Rn = 0.84008… fm. This value is four times the reduced Compton wavelength of the neutron. Assuming the same model for the proton, one obtains a value of Rp = 0.84123… fm, which agrees with the most recent experimental value for the charge radius of the proton within the given limits of error. The neutral charge of the neutron is reproduced, and the positive charge of the proton follows within the model, if the proton is formed via the anti-neutron by losing one electron. S = ±ħ/2, and zero dipole moment, is also reproduced for proton and neutron. Further, a value of the magnetic moment of the neutron of μ= &minus2.00μN (μN: nuclear magnetic moment), and of the proton of μ = 2.666… μN is predicted. The deviation by ca. 5% from the recommended respective values of (&minus1.9130μn), and (2.793μn) is ascribed to the (g-2)-anomaly. Finally, the relation of the model with the established description of the nucleons in terms of three quarks bound by gluons is shortly discussed.
文摘Nucleon-nucleon (NN) correlations and their isospin dependence in asymmetric nuclear matter are of great nterest since they are closely related to the structure of neutron-rich nuclei[1], particle production in heavy-ion ollisions[2], and neutron-star physics[3]. The many-body correlations among nucleons can be directly reflected in the neutron and proton spectral functions[4], and the latter may play an important role in understanding the nature f the NN correlations, especially the short-range and tensor correlations in asymmetric nuclear matter.
文摘The quark and gluon distributions in nuclei are investigated by a parton model,where the common partons of several nucleons and the non-nucleonic components are considered.The comparisons of this model with the data for F_(2)^(A1)(x)/F_(2)^(A2)(x)and the recent data for G_(Sn)(x)/G_(C)(x)are also present.
文摘We study the interaction forces in atomic nuclei based on our expressions for the electrostatic interaction between spheres of arbitrary radii and charges. We prove that at small distances the proton-neutron electrostatic attraction forces are short-range-acting and the proton-proton electrostatic repulsion forces are long-range-acting. We obtain that these forces are commensurate with the nuclear forces. The protonneutron electrostatic attraction forces and the proton-proton electrostatic repulsion forces at the same distance between nucleons differ in absolute value by about an order of magnitude. It follows that based on electromagnetic interactions the neutrons are the binding building blocks in nuclear structures.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11447165,11373047 and 11265009the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2016056
文摘The relativistic neutrino emissivity of the nucleonic direct URCA processes in neutron star matter is investigated within the relativistic Hartree-Fock approximation. We particularly study the influences of the tensor couplings of vector mesons ω and ρ on the nucleonic direct URCA processes. It is found that the inclusion of the tensor couplings of vector mesons w and p can slightly increase the maximum mass of neutron stars. In addition, the results indicate that the tensor couplings of vector mesons ω and ρ lead to obvious enhancement of the total neutrino emissivity for the nucleonic direct URCA processes, which must accelerate the cooling rate of the non- superfluid neutron star matter. However, when considering only the tensor coupling of vector meson ρ, the neutrino emissivity for the nucleonic direct URCA processes slightly declines at low densities and significantly increases at high densities. That is, the tensor coupling of vector meson ρ leads to the slow cooling rate of a low-mass neutron star and rapid cooling rate of a massive neutron star.
基金Supported by the Fundamental Research Funds for the Central Universities under Grant No lzujbky-2014-170the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20120211120002the National Natural Science Foundation of China under Grant Nos 11205075 and 11375076
文摘Within the framework of a semiclassical Boltzmann-Uehling-Uhlenbeck (BUU) transport model, the high mo- mentum tail (HMT) effects of nucleon momentum distribution in the nucleus on the nucleon collective flows are studied in semieentral Au+Au collisions. The HMT due to the isospin-dependent short-range correlations causes a smaller value of the collective flows. We find that the HMT effects on the nucleon collective flows are remarkable at beam energy of 300 MeV/nucleon and become weak as the incident beam energy increases. The results indicate that for the collective flow studies at intermediate energies, the HMT of nucleon momentum distribution in nucleus should be taken into account in transport models.
基金Supported by the National Natural Science Foundation of China under contract Nos 10425521, 10575004 and 106750077 the Key Project of the Ministry of Education of China under Grant No 305001, the Research Fund for the Doctoral Programme of Higher Education of China under Grant No 20040001010, and the Foundation for University Key Teachers by the Ministry of Education of China.
文摘With the Munczek-Nemirovsky model of the effective gluon propagator in the global colour model, we study the radially excited solitons in which one quark is excited and the other two are at the ground state. The obtained masses of the two radial excitations are comparable with the experimental data.
基金Supported by the National Science Foundation of China under Grant Nos 10775072 and 10947160the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20070319007.
文摘By using the chiral quark model and the quark delocalization colour screening model,the phase shifts of nucleonnucleon scattering for high partial waves are studied.The results of both the models are almost equivalent.None of the quark models used have found any resonance-like structure in^(3)F_(2),^(3)F_(3),^(3)F_(4)and^(3)H_(4)partial waves.
基金supported by the China Ministry of Science and Technology (No. 2007CB209903)National Basic Research Program of China(973 Program)
文摘A set of new global phenomenological optical model potential parameters has been obtained in the mass range of target nuclei 220≤A≤260 with incident energies below 300 MeV, by simultaneously fitting the experimental data of 232Th and 23Su, and these potential parameters are analyzed and used to calculate the reaction cross sections, energy spectra and double differ- ential cross sections for p+232Th reaction. Comparison of calculated results using these potential parameters with available experimental data shows that the present form of global optical model potential could reproduce experimental data for both the neutron and the proton.
基金supported by National Natural Science Foundation of China (Nos. 11035001, 11175003, 10875002, 10775005)
文摘The experimental data of the isotopic distribution for projectile-like fragments are presented for the 17,18N + 197Au reaction at 33 MeV/u. The width of the isotopic distributions for lSN projectile is significantly broader than that for 17N projectile, and the average N/Z ratio of the former shifts to higher neutron number side. As long as the realistic nucleon density distribution is used, the isotopic distribution for fragments is reproduced by the simple abrasion-ablation model calculation, which thus provides an independent way to determine the surface distribution of the nuclear matter density for neutron-rich nuclei.
基金Project supported by the Natural Science Foundation of Anhui Province of China (Grant No. 1208085MA09)the Science Research Program of Institutions of Higher Education of Anhui Province of China (Grant No. KJ2012Z297)the Fundamental Research Funds for the Central Universities (Grant No. SWJTU12ZT11)
文摘Using a new set of nucleon coupling constants CZll the properties of a proto neutron star are examined within the framework of the relativistic mean-field theory for the baryon octet system. It is found that the relative number density of A,≡ , and ≡0 for CZll are all smaller than those for GL97 and for both CZ11 and GL97, ∑-∑0 and ∑+ do not appear. It is also found that the pressure and the maximum mass for CZll are all smaller than those for GL97. The maximum mass for CZ11 decreases by approximately 9 percent compared with that for GL97.
文摘The binding energies of all hydrogen isotopes have been calculated successfully for the first time in a previous paper [J Fusion Energy, 30 (2011) 377], using only the electric and magnetic Coulomb’s laws, without using the hypothetical shell model of the nucleus and its mysterious strong force. In this paper, an elementary calculation gives the order of magnitude of the nuclear interaction. The binding energies of the deuteron and the alpha particle are then calculated by taking into account the proton induced electric dipole in the neutron. The large binding energy per nucleon of 4He, as compared to that of 2H, has been explained by a larger electric attraction combined with a lower magnetic repulsion. The binding energies have been calculated without fitting, using only fundamental laws and constants, proving that the nuclear interaction is only electromagnetic.
文摘We compare the static nucleon properties in the Chiral Perturbation Theory (χPT) and the Linear Sigma Model (LSM). We consider a chiral model for the nucleon which is based on the linear sigma model with scalar-isoscalar and scalarisovector mesons coupled to quarks. We have solved the field equations in the mean field approximation for the hedgehog baryon state with different sets of model parameters. A good investigation of some static nucleon properties is obtained by the LSM.