The heat conduction and thermal conductivity for methane hydrate are simulated from equilibrium molecular dynamics. The thermal conductivity and temperature dependence trend agree well with the experimental results. T...The heat conduction and thermal conductivity for methane hydrate are simulated from equilibrium molecular dynamics. The thermal conductivity and temperature dependence trend agree well with the experimental results. The nonmonotonic temperature dependence is attributed to the phonon inelastic scattering at higher temperature and to the confinement of the optic phonon modes and low frequency phonons at low temperature. The thermal conductivity scales proportionally with the van der Waals interaction strength, The conversion of a crystal-like nature into an amorphous one oecurs at higher strength. Both the temperature dependence and interaction strength dependence are explained by phonon inelastic scattering.展开更多
The elastic and inelastic scattering data of 22 MeV protons from <sup>28</sup>Si havebeen measured.The measured differential cross sections were compared with microscop-ic DWBA calculations in which nuclea...The elastic and inelastic scattering data of 22 MeV protons from <sup>28</sup>Si havebeen measured.The measured differential cross sections were compared with microscop-ic DWBA calculations in which nuclear transition densities extracted from (e,e’) exper-iments were used directly.A density-dependent nucleon-nucleon effective interaction inthe low-energy region,Complex Effective Interaction with Gaussian form factor(CEG),was applied in our calculations.Some problems associated were discussed.展开更多
According to the model of equivalent dipoles for active molecules, the analysisof inelastic EM scattering by active molecules embedded in a sphere is given by the method ofdyadic Green’s functions at the first, and t...According to the model of equivalent dipoles for active molecules, the analysisof inelastic EM scattering by active molecules embedded in a sphere is given by the method ofdyadic Green’s functions at the first, and then based on the theory of elastic multiple scattering byrandomly distributed spherical scatterers, a new theory for analysis of inelastic multiple scatteringby active molecules embedded in randomly distributed spherical scatterers also is developed. Thistheory gives the expansions of the multiple scattering fields in all space region in terms of vectorspherical wave functions in which the expansion coefficients can be solved from a set of coupledlinear equations.展开更多
The inelastic collision of protons with sodium atoms are treated for the first time within the framework of the coupledstatic and frozen core approximations. The method is used for calculating partial and total cross-...The inelastic collision of protons with sodium atoms are treated for the first time within the framework of the coupledstatic and frozen core approximations. The method is used for calculating partial and total cross-sections with the assumption that only two channels(elastic and hydrogen formation in 2s state) are open. In each case, the calculations are carried out for seven values of the total angular momentum l(0≤ l≤ 6). The target is described using the Clementi Roetti wave functions within the framework of the one valence electron model. We use Lipmann–Swinger equation to solve the derived equations of the problem, then apply an iterative numerical method to obtain the code of computer to calculate iterative partial cross-sections. This can be done through calculating the reactance matrix at different values of considered energies to obtain the transition matrix that gives partial and total cross sections. The present results for total hydrogen(2s state)formation cross sections are in agreement with results of other available ones in wide range of incident energy.展开更多
An analytic massive total cross section of photon proton scattering is derived, which has geometric scaling. A geometric scaling is used to perform a global analysis of the deep inelastic scattering data on inclusive ...An analytic massive total cross section of photon proton scattering is derived, which has geometric scaling. A geometric scaling is used to perform a global analysis of the deep inelastic scattering data on inclusive structure function F2 measured in lepton-hadron scattering experiments at small values of Bjorken x. It is shown that the descriptions of the inclusive structure function F2 and longitudinal structure function FL are improved with the massive analytic structure function, which may imply the gluon saturation effect dominating the parton evolution process at HERA. The inclusion of the heavy quarks prevent the divergence of the lepton-hadron cross section, which plays a significant role in the description of the photoproduction region.展开更多
Proton inelastic scatterings from several s-d shell nuclei are analyzed using optical potential model and collective model in Dirac coupled channel formalism. The optical potential parameters obtained phenomenological...Proton inelastic scatterings from several s-d shell nuclei are analyzed using optical potential model and collective model in Dirac coupled channel formalism. The optical potential parameters obtained phenomenologically for the scatterings from the s-d shell nuclei are compared with each other for systematic Dirac analysis. Dirac equations are reduced to the second-order differential equations in order to obtain the Schroedinger equivalent effective central and spin-orbit optical potentials, and the surface-peaked phenomena are observed at the real effective central potentials for the scatterings from 22Ne, 20Ne and 24Mg. By analyzing the obtained effective spin-orbit potentials, it is confirmed that the spin-orbit interaction is a surface-peaked interaction. The first-order rotational collective models are used to describe the low-lying excited states of the ground state rotational bands in the s-d shell deformed nuclei, and the obtained deformation parameters are analyzed by comparing with each other, and compared with those obtained by using the nonrelativistic calculations. The obtained deformation parameters of Dirac phenomenological calculations for the s-d shell nuclei are found to agree pretty well with those of the nonrelativistic calculations using the same Woods-Saxon potential shape, even though the theoretical bases are quite different.展开更多
Fully A-doublet resolved differential cross sections and collision-induced rotational alignment moments have been measured for the NO(X)-Xe collision system at a collision energy of 519 cm^-1.The experiments combine i...Fully A-doublet resolved differential cross sections and collision-induced rotational alignment moments have been measured for the NO(X)-Xe collision system at a collision energy of 519 cm^-1.The experiments combine initial quantum state selection,employing a hexapole inhomogeneous electric field,with quantum state resolved detection,using(1+1')resonantly enhanced multiphoton ionization and velocity map ion imaging.The differential cross sections and polarization dependent differential cross sections are shown to agree well with quantum mechanical scattering calculations performed on ab initio potential energy surfaces[J.Klos et al.J.Chem.Phys.137,014312(2012)].By comparison with quasi-classical trajectory calculations,quantum mechanical scattering calculations on a hard-shell potential,and kinematic apse model calculations,the effects of the attractive part of the potential on the measured differential cross sections and collision-induced rotational alignment moments are assessed.展开更多
We study the effects of running coupling and gluon number fluctuations in the latest diffractive deep inelastic scattering data. It is found that the description of the data is improved once the running coupling and g...We study the effects of running coupling and gluon number fluctuations in the latest diffractive deep inelastic scattering data. It is found that the description of the data is improved once the running coupling and gluon number fluctuations are included with x2/d.o.f. = 0.867, x2/d.o.f. = 0.923 and x2/d.o.f. = 0.878 for three different groups of experimental data. The values of diffusive coefficient subtracted from the fit are smaller than the ones obtained by considering only the gluon number fluctuations in our previous studies. The smaller values of the diffusive coefficient are in agreement with the theoretical predictions, where the gluon number fluctuations are suppressed by the running coupling which leads to smaller values of the diffusive coefficient.展开更多
The oscillator strengths of the valence-shell excitations of C_(2)H_(2) are extremely important for testing theoretical models and studying interstellar gases.In this study,the high-resolution inelastic x-ray scatteri...The oscillator strengths of the valence-shell excitations of C_(2)H_(2) are extremely important for testing theoretical models and studying interstellar gases.In this study,the high-resolution inelastic x-ray scattering(IXS)method is adopted to determine the generalized oscillator strengths(GOSs)of the valence-shell excitations of C_(2)H_(2) at a photon energy of10 ke V.The GOSs are extrapolated to their zero limit to obtain the corresponding optical oscillator strengths(OOSs).Through taking a completely different experimental method of the IXS,the present results offer the high energy limit for electron collision to satisfy the first Born approximation(FBA)and cross-check the previous experimental and theoretical results independently.The comparisons indicate that an electron collision energy of 1500 e V is not enough for C_(2)H_(2) to satisfy the FBA for the large squared momentum transfer,and the line saturation effect limits the accuracy of the OOSs measured by the photoabsorption method.展开更多
When high voltage is applied to distilled water filled into two beakers close to each other, a watery connection forms spontaneously, giving the impression of a floating water bridge [1-8]. In this work we present the...When high voltage is applied to distilled water filled into two beakers close to each other, a watery connection forms spontaneously, giving the impression of a floating water bridge [1-8]. In this work we present the first inelastic ultraviolet scattering data of such an electrohydrodynamic bridge revealing radial gradients of Stokes- and Anti-Stokes shifts and their intensity profiles. Interpretations including density and temperature changes within the bridge are discussed. The obtained data can be satisfactorily explained by the introduction of a second phase consisting of nano bubbles. Results and interpretation are discussed in relation to similar phenomena.展开更多
The differential elastic and inelastic scattering neutron cross sections of <sup>12</sup>C atE<sub>n</sub>=14.7 MeV produced by the T(d,n)<sup>4</sup>He reaction were measured usi...The differential elastic and inelastic scattering neutron cross sections of <sup>12</sup>C atE<sub>n</sub>=14.7 MeV produced by the T(d,n)<sup>4</sup>He reaction were measured using an associatedparticle fast neutron TOF spectrometer at 15 angles ranging from 15° to 130°.Theflight path was 2.54 m.The neutron detector consisting of an ST-451 liquid scintillatorwas massively shielded.展开更多
The differential cross sections of the inelastic scattering of antiproton leading to the2<sup>+</sup> excited stae of <sup>18</sup>O are calculated at 178.4 MeV by the Eikonal approximation and...The differential cross sections of the inelastic scattering of antiproton leading to the2<sup>+</sup> excited stae of <sup>18</sup>O are calculated at 178.4 MeV by the Eikonal approximation and thecollective model of nucleus.It may be concluded that the 2<sup>+</sup> state is a quadruple rotationalstate.The results are in good agreement with experimental data.展开更多
The microscopic DWBA was used to calculate the inelastic neutron scattering on <sup>11</sup>B to 2.14MeV excited state and some energy dependent parameters were used to improve the calculation.The inte-gra...The microscopic DWBA was used to calculate the inelastic neutron scattering on <sup>11</sup>B to 2.14MeV excited state and some energy dependent parameters were used to improve the calculation.The inte-grated inelastic cross sections and the angular distributions of the <sup>11</sup>B(n,n′)<sup>11</sup>B*(2.14 MeV excitedstate)were given for the incident neutrons whose energy varies from 7.54 MeV to 20.0 MeV.Resultswere also given for the experimental blank data.展开更多
The microscopic DWBA was used to calculate the inelastic neutron scatteringon <sup>12</sup>C to 4.44 MeV excited state and some energy dependent parameters were used toimprove the calculation.The inelastic...The microscopic DWBA was used to calculate the inelastic neutron scatteringon <sup>12</sup>C to 4.44 MeV excited state and some energy dependent parameters were used toimprove the calculation.The inelastic integrated cross sections and the angular distribu-tions of <sup>12</sup>C(n,n’)<sup>12</sup>C 4.44 MeV excited state were given for the incident neutron whoseenergy varies from 7.0 MeV to 20.0 MeV.Results were also given for the experimentalblank data.展开更多
In the present paper, the inelastic mean free path (IMFP) of incident electrons is calculated as a function of energy for silicon (Si), oxides of silicon (SiO2), SiO, and A1203 in bulk form by employing atomic/m...In the present paper, the inelastic mean free path (IMFP) of incident electrons is calculated as a function of energy for silicon (Si), oxides of silicon (SiO2), SiO, and A1203 in bulk form by employing atomic/molecular inelastic cross sections derived by using a semi-empirical quantum mechanical method developed earlier. A general agreement of the present results is found with most of the available data. It is of great importance that we have been able to estimate the minimum IMFP, which corresponds to the peak of inelastic interactions of incident electrons in each solid investigated. New results are presented for SiO, for which no comparison is available. The present work is important in view of the lack of experimental data on the IMFP in solids.展开更多
We demonstrate a possibility of computation of inelastic scattering cross-section in a multi-peripheral model by application of the Laplace method to multidimensional integral over the domain of physical process. Foun...We demonstrate a possibility of computation of inelastic scattering cross-section in a multi-peripheral model by application of the Laplace method to multidimensional integral over the domain of physical process. Founded the constrained maximum point of scattering cross-section integral under condition of the energy-momentum conservation. The integrand is substituted for an expression of Gaussian type in the neighborhood of this point. It made possible to compute this integral numerically. The paper has two parts. The hunting procedure of the constrained maximum point is considered and the properties of this maximum point are discussed in the given part of the paper. It is shown that virtuality of all internal lines of the “comb” diagram reduced at the constrained maximum point with energy growth. In the second part of the paper we give some the arguments in favor of consideration of the mechanism of virtuality reduction as the mechanism of the total hadron scattering cross-section growth, which is not taken into account within the framework of Regge theory.展开更多
We demonstrate a new technique for calculating proton-proton inelastic cross-section, which allows one by application of the Laplace' method replace the integrand in the integral for the scattering amplitude in th...We demonstrate a new technique for calculating proton-proton inelastic cross-section, which allows one by application of the Laplace' method replace the integrand in the integral for the scattering amplitude in the vicinity of the maximum point by expression of Gaussian type. This, in turn, allows us to overcome the computational difficulties for the calculation of the integrals expressing the cross section to sufficiently large numbers of particles. We have managed to overcome these problems in calculating the proton-proton inelastic cross-section for production (n ≤ 8) number of secondary particles in within the framework of φ3 model. As the result the obtained dependence of inelastic cross-section and total scattering cross-section on the energy √s are qualitative agrees with the experimental data. Such description of total cross-section behavior differs considerably from existing now description, where reggeons exchange with the intercept greater than unity is considered.展开更多
We develop a new method for taking into account the interference contributions to proton-proton inelastic cross-section within the framework of the simplest multi-peripheral model based on the self-interacting scalar ...We develop a new method for taking into account the interference contributions to proton-proton inelastic cross-section within the framework of the simplest multi-peripheral model based on the self-interacting scalar φ3 field theory, using Laplace’s method for calculation of each interference contribution. We do not know any works that adopted the inter- ference contributions for inelastic processes. This is due to the generally adopted assumption that the main contribution to the integrals expressing the cross section makes multi-Regge domains with its characteristic strong ordering of secon- dary particles by rapidity. However, in this work, we find what kind of space domains makes a major contribution to the integral and these space domains are not multi-Regge. We demonstrated that because these interference contributions are significant, so they cannot be limited by a small part of them. With the help of the approximate replacement the sum of a huge number of these contributions by the integral were calculated partial cross sections for such numbers of secondary particles for which direct calculation would be impossible. The offered model qualitative agrees with experimental dependence of total scattering cross-section on energy with a characteristic minimum in the range ≈ 10 GeV. However, quantitative agreement was not achieved;we assume that due to the fact that we have examined the simplest diagrams of theory.展开更多
In the first Born approximation,we study the reactions Kφ→πK,ρK,πK*,and ρK*with quark-antiquark annihilation and creation.Transition amplitudes are derived with the development in the spherical harmonics of the ...In the first Born approximation,we study the reactions Kφ→πK,ρK,πK*,and ρK*with quark-antiquark annihilation and creation.Transition amplitudes are derived with the development in the spherical harmonics of the relative-motion wave functions of two initial mesons and two final mesons so that parity is conserved and the total angular momentum of the final mesons equals that of the initial mesons.Unpolarized cross sections are calculated from the transition amplitudes that also contain mesonic quark-antiquark relative-motion wave functions and transition potentials for quark-antiquark annihilation and creation.The notable temperature dependence of the cross sections is shown.The cross sections for Kφ→ρK,Kφ→K*,and Kφ→ρK*may be of the millibarn scale,whereas the cross section for Kφ→πK is small.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos U1262112 and 51176205
文摘The heat conduction and thermal conductivity for methane hydrate are simulated from equilibrium molecular dynamics. The thermal conductivity and temperature dependence trend agree well with the experimental results. The nonmonotonic temperature dependence is attributed to the phonon inelastic scattering at higher temperature and to the confinement of the optic phonon modes and low frequency phonons at low temperature. The thermal conductivity scales proportionally with the van der Waals interaction strength, The conversion of a crystal-like nature into an amorphous one oecurs at higher strength. Both the temperature dependence and interaction strength dependence are explained by phonon inelastic scattering.
文摘The elastic and inelastic scattering data of 22 MeV protons from <sup>28</sup>Si havebeen measured.The measured differential cross sections were compared with microscop-ic DWBA calculations in which nuclear transition densities extracted from (e,e’) exper-iments were used directly.A density-dependent nucleon-nucleon effective interaction inthe low-energy region,Complex Effective Interaction with Gaussian form factor(CEG),was applied in our calculations.Some problems associated were discussed.
文摘According to the model of equivalent dipoles for active molecules, the analysisof inelastic EM scattering by active molecules embedded in a sphere is given by the method ofdyadic Green’s functions at the first, and then based on the theory of elastic multiple scattering byrandomly distributed spherical scatterers, a new theory for analysis of inelastic multiple scatteringby active molecules embedded in randomly distributed spherical scatterers also is developed. Thistheory gives the expansions of the multiple scattering fields in all space region in terms of vectorspherical wave functions in which the expansion coefficients can be solved from a set of coupledlinear equations.
文摘The inelastic collision of protons with sodium atoms are treated for the first time within the framework of the coupledstatic and frozen core approximations. The method is used for calculating partial and total cross-sections with the assumption that only two channels(elastic and hydrogen formation in 2s state) are open. In each case, the calculations are carried out for seven values of the total angular momentum l(0≤ l≤ 6). The target is described using the Clementi Roetti wave functions within the framework of the one valence electron model. We use Lipmann–Swinger equation to solve the derived equations of the problem, then apply an iterative numerical method to obtain the code of computer to calculate iterative partial cross-sections. This can be done through calculating the reactance matrix at different values of considered energies to obtain the transition matrix that gives partial and total cross sections. The present results for total hydrogen(2s state)formation cross sections are in agreement with results of other available ones in wide range of incident energy.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11305040,11375071 and 11447203the Education Department of Guizhou Province Innovation Talent Fund under Grant No[2015]5508+2 种基金the Education Department of Guizhou Province Innovation Team Fund under Grant No[2014]35the Guizhou Province Science Technology Foundation under Grant No[2015]2114the Guizhou Province Innovation Talent Team Fund under Grant No[2015]4015
文摘An analytic massive total cross section of photon proton scattering is derived, which has geometric scaling. A geometric scaling is used to perform a global analysis of the deep inelastic scattering data on inclusive structure function F2 measured in lepton-hadron scattering experiments at small values of Bjorken x. It is shown that the descriptions of the inclusive structure function F2 and longitudinal structure function FL are improved with the massive analytic structure function, which may imply the gluon saturation effect dominating the parton evolution process at HERA. The inclusion of the heavy quarks prevent the divergence of the lepton-hadron cross section, which plays a significant role in the description of the photoproduction region.
文摘Proton inelastic scatterings from several s-d shell nuclei are analyzed using optical potential model and collective model in Dirac coupled channel formalism. The optical potential parameters obtained phenomenologically for the scatterings from the s-d shell nuclei are compared with each other for systematic Dirac analysis. Dirac equations are reduced to the second-order differential equations in order to obtain the Schroedinger equivalent effective central and spin-orbit optical potentials, and the surface-peaked phenomena are observed at the real effective central potentials for the scatterings from 22Ne, 20Ne and 24Mg. By analyzing the obtained effective spin-orbit potentials, it is confirmed that the spin-orbit interaction is a surface-peaked interaction. The first-order rotational collective models are used to describe the low-lying excited states of the ground state rotational bands in the s-d shell deformed nuclei, and the obtained deformation parameters are analyzed by comparing with each other, and compared with those obtained by using the nonrelativistic calculations. The obtained deformation parameters of Dirac phenomenological calculations for the s-d shell nuclei are found to agree pretty well with those of the nonrelativistic calculations using the same Woods-Saxon potential shape, even though the theoretical bases are quite different.
基金The support of the UK EPSRC to Mark Brouard via Programme Grant EP/L005913/1the Spanish Ministry of Science and Innovation(Grant PGC2018-096444-B-I00 MINECO/FEDER)to F.Javier Aoiz are gratefully acknowledged+2 种基金funding by Fundación Salamanca City of Culture and Knowledge(Programme for attracting Scientific Talent to Salamanca)support through U.S.National Science Foundation under Grant No.CHE-1565872 to Millard H.Alexander.
文摘Fully A-doublet resolved differential cross sections and collision-induced rotational alignment moments have been measured for the NO(X)-Xe collision system at a collision energy of 519 cm^-1.The experiments combine initial quantum state selection,employing a hexapole inhomogeneous electric field,with quantum state resolved detection,using(1+1')resonantly enhanced multiphoton ionization and velocity map ion imaging.The differential cross sections and polarization dependent differential cross sections are shown to agree well with quantum mechanical scattering calculations performed on ab initio potential energy surfaces[J.Klos et al.J.Chem.Phys.137,014312(2012)].By comparison with quasi-classical trajectory calculations,quantum mechanical scattering calculations on a hard-shell potential,and kinematic apse model calculations,the effects of the attractive part of the potential on the measured differential cross sections and collision-induced rotational alignment moments are assessed.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11305040,11505036 and 11447203the Education Department of Guizhou Province Talent Fund under Grant No[2015]5508the Science and Technology Department of Guizhou Province Fund under Grant Nos[2015]2114 and [2014]7053
文摘We study the effects of running coupling and gluon number fluctuations in the latest diffractive deep inelastic scattering data. It is found that the description of the data is improved once the running coupling and gluon number fluctuations are included with x2/d.o.f. = 0.867, x2/d.o.f. = 0.923 and x2/d.o.f. = 0.878 for three different groups of experimental data. The values of diffusive coefficient subtracted from the fit are smaller than the ones obtained by considering only the gluon number fluctuations in our previous studies. The smaller values of the diffusive coefficient are in agreement with the theoretical predictions, where the gluon number fluctuations are suppressed by the running coupling which leads to smaller values of the diffusive coefficient.
基金Project supported by the Strategic Priority Research Program of the Chinese Academy of Science(Grant No.XDB34000000)the National Natural Science Foundation of China(Grant Nos.U1932207 and 12104437)+3 种基金the National Key Research and Development Program of China(Grant No.2017YFA0402300)The support from the Heavy Ion Research Facility in Lanzhou(HIRFL)the BL12XU of SPring-8 with the approval of Japan Synchrotron Radiation Research Institute(Proposal No.2019A4275)“National”Synchrotron Radiation Research Center,Taiwan,China(Proposal No.2019-2-089-1)。
文摘The oscillator strengths of the valence-shell excitations of C_(2)H_(2) are extremely important for testing theoretical models and studying interstellar gases.In this study,the high-resolution inelastic x-ray scattering(IXS)method is adopted to determine the generalized oscillator strengths(GOSs)of the valence-shell excitations of C_(2)H_(2) at a photon energy of10 ke V.The GOSs are extrapolated to their zero limit to obtain the corresponding optical oscillator strengths(OOSs).Through taking a completely different experimental method of the IXS,the present results offer the high energy limit for electron collision to satisfy the first Born approximation(FBA)and cross-check the previous experimental and theoretical results independently.The comparisons indicate that an electron collision energy of 1500 e V is not enough for C_(2)H_(2) to satisfy the FBA for the large squared momentum transfer,and the line saturation effect limits the accuracy of the OOSs measured by the photoabsorption method.
文摘When high voltage is applied to distilled water filled into two beakers close to each other, a watery connection forms spontaneously, giving the impression of a floating water bridge [1-8]. In this work we present the first inelastic ultraviolet scattering data of such an electrohydrodynamic bridge revealing radial gradients of Stokes- and Anti-Stokes shifts and their intensity profiles. Interpretations including density and temperature changes within the bridge are discussed. The obtained data can be satisfactorily explained by the introduction of a second phase consisting of nano bubbles. Results and interpretation are discussed in relation to similar phenomena.
文摘The differential elastic and inelastic scattering neutron cross sections of <sup>12</sup>C atE<sub>n</sub>=14.7 MeV produced by the T(d,n)<sup>4</sup>He reaction were measured using an associatedparticle fast neutron TOF spectrometer at 15 angles ranging from 15° to 130°.Theflight path was 2.54 m.The neutron detector consisting of an ST-451 liquid scintillatorwas massively shielded.
文摘The differential cross sections of the inelastic scattering of antiproton leading to the2<sup>+</sup> excited stae of <sup>18</sup>O are calculated at 178.4 MeV by the Eikonal approximation and thecollective model of nucleus.It may be concluded that the 2<sup>+</sup> state is a quadruple rotationalstate.The results are in good agreement with experimental data.
文摘The microscopic DWBA was used to calculate the inelastic neutron scattering on <sup>11</sup>B to 2.14MeV excited state and some energy dependent parameters were used to improve the calculation.The inte-grated inelastic cross sections and the angular distributions of the <sup>11</sup>B(n,n′)<sup>11</sup>B*(2.14 MeV excitedstate)were given for the incident neutrons whose energy varies from 7.54 MeV to 20.0 MeV.Resultswere also given for the experimental blank data.
文摘The microscopic DWBA was used to calculate the inelastic neutron scatteringon <sup>12</sup>C to 4.44 MeV excited state and some energy dependent parameters were used toimprove the calculation.The inelastic integrated cross sections and the angular distribu-tions of <sup>12</sup>C(n,n’)<sup>12</sup>C 4.44 MeV excited state were given for the incident neutron whoseenergy varies from 7.0 MeV to 20.0 MeV.Results were also given for the experimentalblank data.
基金Project supported by the Indian Space Research Organization through Respond Project (Grant No.ISRO/RES/2/356/10-11)
文摘In the present paper, the inelastic mean free path (IMFP) of incident electrons is calculated as a function of energy for silicon (Si), oxides of silicon (SiO2), SiO, and A1203 in bulk form by employing atomic/molecular inelastic cross sections derived by using a semi-empirical quantum mechanical method developed earlier. A general agreement of the present results is found with most of the available data. It is of great importance that we have been able to estimate the minimum IMFP, which corresponds to the peak of inelastic interactions of incident electrons in each solid investigated. New results are presented for SiO, for which no comparison is available. The present work is important in view of the lack of experimental data on the IMFP in solids.
文摘We demonstrate a possibility of computation of inelastic scattering cross-section in a multi-peripheral model by application of the Laplace method to multidimensional integral over the domain of physical process. Founded the constrained maximum point of scattering cross-section integral under condition of the energy-momentum conservation. The integrand is substituted for an expression of Gaussian type in the neighborhood of this point. It made possible to compute this integral numerically. The paper has two parts. The hunting procedure of the constrained maximum point is considered and the properties of this maximum point are discussed in the given part of the paper. It is shown that virtuality of all internal lines of the “comb” diagram reduced at the constrained maximum point with energy growth. In the second part of the paper we give some the arguments in favor of consideration of the mechanism of virtuality reduction as the mechanism of the total hadron scattering cross-section growth, which is not taken into account within the framework of Regge theory.
文摘We demonstrate a new technique for calculating proton-proton inelastic cross-section, which allows one by application of the Laplace' method replace the integrand in the integral for the scattering amplitude in the vicinity of the maximum point by expression of Gaussian type. This, in turn, allows us to overcome the computational difficulties for the calculation of the integrals expressing the cross section to sufficiently large numbers of particles. We have managed to overcome these problems in calculating the proton-proton inelastic cross-section for production (n ≤ 8) number of secondary particles in within the framework of φ3 model. As the result the obtained dependence of inelastic cross-section and total scattering cross-section on the energy √s are qualitative agrees with the experimental data. Such description of total cross-section behavior differs considerably from existing now description, where reggeons exchange with the intercept greater than unity is considered.
文摘We develop a new method for taking into account the interference contributions to proton-proton inelastic cross-section within the framework of the simplest multi-peripheral model based on the self-interacting scalar φ3 field theory, using Laplace’s method for calculation of each interference contribution. We do not know any works that adopted the inter- ference contributions for inelastic processes. This is due to the generally adopted assumption that the main contribution to the integrals expressing the cross section makes multi-Regge domains with its characteristic strong ordering of secon- dary particles by rapidity. However, in this work, we find what kind of space domains makes a major contribution to the integral and these space domains are not multi-Regge. We demonstrated that because these interference contributions are significant, so they cannot be limited by a small part of them. With the help of the approximate replacement the sum of a huge number of these contributions by the integral were calculated partial cross sections for such numbers of secondary particles for which direct calculation would be impossible. The offered model qualitative agrees with experimental dependence of total scattering cross-section on energy with a characteristic minimum in the range ≈ 10 GeV. However, quantitative agreement was not achieved;we assume that due to the fact that we have examined the simplest diagrams of theory.
基金Supported by the National Natural Science Foundation of China(11175111)。
文摘In the first Born approximation,we study the reactions Kφ→πK,ρK,πK*,and ρK*with quark-antiquark annihilation and creation.Transition amplitudes are derived with the development in the spherical harmonics of the relative-motion wave functions of two initial mesons and two final mesons so that parity is conserved and the total angular momentum of the final mesons equals that of the initial mesons.Unpolarized cross sections are calculated from the transition amplitudes that also contain mesonic quark-antiquark relative-motion wave functions and transition potentials for quark-antiquark annihilation and creation.The notable temperature dependence of the cross sections is shown.The cross sections for Kφ→ρK,Kφ→K*,and Kφ→ρK*may be of the millibarn scale,whereas the cross section for Kφ→πK is small.