共查询到20条相似文献,搜索用时 15 毫秒
1.
The elastic scattering of electrons on the cut-off Coulomb potential Uc(r) = ?1/r + 1/rc, for r ≦ rc and Uc(r) = 0, for r > rc, has been considered. It has been shown that for ε > 0.5/rc (ε is the energy of free electrons in atomic units) the analytical quasi-classical expressions describe quite well the behaviour of transport, differential and total cross sections for elastic scattering. It has been shown moreover, that in the energy range considered, transport cross section could be determined with practically the same accuracy already by means of classical, analytical expressions. Born approximations show larger deviations from exact quantum calculations. 相似文献
2.
It ia shown that the differential cross section for both K+p and K-p elastic scattering including the most recent measurements for 20 < pL < 200 (GeV/c) and with -t extended upto 28 (GeV/c)2 can be fitted by using the pomeron as dipole and p as a simple pole. The difference of the total cross section for K+p and K-p scattering is also explained. 相似文献
3.
Gerhard J. Wagner 《Czechoslovak Journal of Physics》1999,49(9):1383-1409
Pion-nucleon scattering and charge-exchange experiments aim at a determination of the pion-nucleon coupling constant, the sigma term of chiral symmetry breaking in non-perturbative QCD and the possible isospin breaking of strong interactions. A review of the present situation shows that the accuracy of the results is still limited by the existing data base despite 20 years of experimental efforts at meson factories. The present new generation of experiments at PSI and TRIUMF, using novel instrumentation, promises considerable progress. 相似文献
4.
ZHOU Li-Juan MA Wei-Xing 《理论物理通讯》2007,48(3):541-544
5.
The low energy scattering of electrons by sodium at incident energies up to ionization threshold are calculated by applying the momentum space coupled-channel-optical (CCO) method. The present results are in good agreement with the previous experimental and theoretical results. Furthermore, three resonances in the total cross sections observed by previous experiments are proved by the present calculation. 相似文献
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We discuss the low-energy behaviour of the virtual Compton scattering amplitude off a spin-zero target. We first compare various
methods of obtaining a low-energy expression based either on the soft-photon approximation or the use of Ward-Takahashi identities.
We point out that structure-dependent terms are defined with respect to a low-energy approximation of the pole terms, which
commonly is separated from the full amplitude. We derive a general expression for the structure-dependent terms in an expansion
in terms of the momenta and of the initial and final virtual photon, respectively, up to and including terms of order . At order two terms appear that are related to the usual electric and magnetic polarizabilities of real Compton scattering. At order
we find nine new structures of which five can only be determined using virtual photons.
Received October 23, 1997; accepted for publication December 29, 1997 相似文献
8.
ZHANG Yu-shun 《理论物理通讯》1989,12(2):179-186
In this paper, by using the collective coordinate of A. Bohr and phenomenological deformed optical potential and Coulomb interaction, the scattering amplitude of two composite particle systems can be obtained. The differential cross sections for the 0+, 2+, 4+ and 6+, p(0.8 GeV)+154Sm and p (0.8 Gev)+176Yb are calculated. The results show that the Coulomb effect is quite important. 相似文献
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Elastic scattering by 3He for 1.67, 2.43, 3.0, 3.4 and 7.8 MeV neutron beams of known polarization was measured at seven angles from 25° to 155° using a high pressure gas scintillation counter. The geometrical and multiple scattering effects were accounted for by the Monte Carlo technique. The corrected results were compared with previous experimental data and with the existing predictions based on microscopic calculations and phenomenological analyses. 相似文献
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In this paper, exact solutions of scattering states of the Klein-Gordon equation with Coulomb potential plus
a new ring-shaped potential are studied under the condition that
the scalar potential is equal to the vector potential. The normalized
wave functions of scattering states on the “k/2π scale” and the calculation formula of phase shifts are presented. Analytical properties of the scattering amplitude are discussed. 相似文献
14.
The motivation of this paper is to obtain the three-body amplitudes for the Coulomb potential plus a nuclear force in momentum space. Not only the two-body off-shell nuclear amplitude but also the two-body off-shell Coulomb amplitude is important in the three-body calculation. For calculating the Coulomb amplitude, the modified Coulomb potential whose Fourier transformation is analytically equivalent to the pure configuration space Coulomb potential, is introduced. In addition, the decisive screening range parameter is also utilized instead of the screening range. The modified Coulomb potential plus the parameter is called decisive modified Coulomb potential. The three-body proton-deuteron elastic scattering is calculated by using the proper two-body off-shell amplitude for the decisive modified Coulomb potential. 相似文献
15.
中能区反质子与核的非弹性散射 总被引:1,自引:0,他引:1
运用多次散射理论的光学势获得反质子的扭曲波.在扭曲波冲量近似下,讨论了中能区反质子与原子核的非弹性散射.考虑了反质子能量从180MeV到1800MeV这一能区12C,的2+,3-态微分截面.在这一能区的低能端,(E=180MeV)DWIA能够很好的符合实验,同时,预示了更高能量可能出现的微分截面的理论结果. 相似文献
16.
Li Yangguo 《中国物理C(英文版)》1994,18(2):186-192
The distorted wave of antiproton is obtained by an optical potential derived from the multiple scattering theory In the framework of the distorted wave impulseapproximation, we discuss the antiproton-nucleus inelastic scattering at intermediate energies. The inelastic differential cross sections of 2+, 3- states at antiproton energies from 180 MeV to 1800 MeV are calculated. It is shown that DWIA fitted the experimented data quite well, and theoretical results of inelastic cross sections at higher energies are predicted. 相似文献
17.
The problem of two relativistically-moving pointlike particles of constant mass is undertaken in an arbitrary Lorentz frame using the classical Lagrangian mechanics of Stückelberg, Horwitz, and Piron. The particles are assumed to interact at events along their world lines at a common world time, an invariant dynamical parameter which is not in general synchronous with the particle proper time. The Lorentz-scalar interaction is assumed to be the Coulomb potential (i.e., the inverse square spacetime potential) of the spacetime event separation. The classical orbit equations are found in 1 + 1 spacetime dimensions in the hyperbolic angle coordinates for the reduced problem. The solutions to the reduced motion in these coordinates are the spacetime generalizations of the nonrelativistic Kepler solutions. and they introduce an invariant eccentricity which is a function of other known constants of the motion for the reduced problem. Solutions compatible with physical scattering are obtained by the assumption that the eccentricity is a given function of the ratio of the particle masses. 相似文献
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New results are obtained from which it follows that systematic use of the one-to-one correspondence between a physical quantity and an operator, which permits the existence of a non-negative quantum distribution function, leads to an effective smearing of the potential and to the appearance of a form factor, i.e., to the existence of structure in the scattering center.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 16–19, April, 1980. 相似文献
20.
The Coulomb effect in high energy antiproton-nucleus elastic and inelastic
scattering from 12C and
16O is studied in the framework of Glauber multiple
scattering theory for five kinetic energies ranged from 0.23 to 1.83 GeV. A microscopic shell-model nuclear wave functions, Woods-Saxon single-particle wave functions, and experimental
pN amplitudes are used in the calculations. The results show that
the Coulomb effect is of paramount importance for filling up the dips of differential cross sections. We claim that the present result for inelastic scattering of
antiproton-12C is sufficiently reliable to be a guide for measurements in the very
near future. We also believe that antiproton nucleus elastic and inelastic scattering
may produce new information on both the nuclear structure and the antinucleon-nucleon interaction, in particular the
p-neutron interaction. 相似文献