1981 Vol. 5, No. 3
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The properties of fermion causal Green's function is discussed according to the theory of spectral representation. The definition of effective mass is established from the view point of field theory, and the approximate expression of SF' (p) as |p2|«M2 and the asymptotic formula of SF' (p) as p2→+∞ is given. In terms of these result the problem of quark confinement is discussed. We find that: (ⅰ) Based on the theory of spectral re presentation the concept of relative confinement is allowed, and if renormalization effect is strong, the quarks can demonstrate definitely lighter effective mass when they are far away from the mass shell; (ⅱ) Based on the theory of spectral representation the concept of absolute confinement is unallowable, even the absolute confinement is taken as the limit of relative confinement. That is if the concept of absolute confinement is introduced, we must discard a part of elementary hypothesis of spectral representation theory.
Using elastic unitary condition of t channel, the double spectral function of photon-nucleon scattering and absorbtive parts of scattering amplitude (s channel) are given. Using date of low energy πN(3,3) resonance ρ resonance, the photo-production cross-sections of γ+q+q+π++π- are calculated. The results are compared with the recent experimental data.
Extending the elementary amplitude in the Glauber Theory and using α-α scattering amplitude as the elementary amplitude, the high energy nuclei-nuclei collision is discussed. In this paper, high energy alpha scattering by C12 is calculated in detail and satisfactory results are obtained.
In this paper a SU(2)×U(1)×S3 model with two Higgs doublets is discussed in detail. It is shown that besides the case discussed by Segre et al., there is another physically interesting case. We investigate the latter in detail. In This case, taking the quark masses and the Cabibbo angle θ1 as input parameters, we can obtain Cabibbo angles θ2 and θ3 which have the same order of magnitude as θ1. Finally the appearance of a pseudo Goldstone boson in the model is discussed, a method to overcome the difficulty is given, and the physical results of this case which do not contradict with the experiments are discussed.
The problem of four generation straton weak coupling matrix is discussed. In several possibilities, the V-A coupling for the electroweak interaction of the four generation stratons is chosen and a coupling matrix of charged weak currents is proposed. It is a direct extension of K-M matrix. In order to illustrate the validity of the weak coupling matrix, two examples are given. The first example is used for the calculation of CP violation of K decays. In the second example, four generation weak coupling matrix expressed by mass of straton is calculated by means of horizontal gauge. An unexpected result is that the main decay mode of b straton is b→c+W-. But in the case of 3 generations, the main decay mode of b straton obtained by the entirely similar model is b→u+W-. Therefore, if this mode of horizontal gauge be verified in further experiments, there would be a reason for the extension of 3 generations to 4 generations.
From the relativistic semiclassieal theory of π condensation, we deduced that, in the σ model, because of the variation of the radius of the magic circle with nuclear density, the π condensation in nuclear matter is possible. The calculated critical density is slightly higher than that of the normal ground state nuclear matter.
Under Quasi-△33 Doorway state model of π nucleus scattering, the differential cross sections and total cross sections of elastic π-4He and π-40Ca at the different incident energies, (Txlab=110, 150, 180, 220, 260 MeV for π-4He, Txlab=115.5, 163.3, 241.0 MeV for π-40Ca) are calculated. The approximate agreement between the theoretical results and experimential data is arrived at.We evaluate further the correction of spin-orbite coupling effects for π-4He, and the better agreements with experimential data are obtained.
The beam envelops for non-periodic alternating gradient focusing system is analysed. The accurate analytic expressions of the beam envelop function β is obtained by solving the following non-linear differential equation:(√β)н+Q(Z)√β-1/(√β)3=0,
The conditions of existing the maximum and the minimum of beam envelop are discussed. And we have derived the accurate formulae with which one can calculate the maximum and the minimum values of envelop and their position. The method developed in this paper is different from the convintional matrix computational method. Both methods can be checked by each other.
The purpose of this paper is to study, the A-N interaction by using meson exchange theory. We have considered three processes: ⅰ) Single K meson exchange, ⅱ) Box diagrams of 2π and πρ exchanges with a nucleon in the intermediate states, and ⅲ) Box diagrams of 2π and πρ exchange with an isobar in the intermediate states. For simplicity, two approximations are used in the calculation. First, the initial nucleon N and hyperon are considered to be at rest. Second, an average value is used for the energies of the intermediate states. The results are qualitatively consistent with experiments.
Many Suggestions have been made for accelerating particles in the intense fields associated with laser light. Those which rely on direct interaction with the laser field in vacuo (as opposed to acceleration in a plasma medium) are examined and their fundamental limitations discussed. Three schemes are considered, the first of these utilizes slow electromagnetic waves near a surface, the second relies on a fast electromagnetic wave with "phase jumps" and the third used parametric interaction with particles moving on a modulated orbit.
A realistic calculation of the viscosity coefficients for 236U from ground equilibrium shape to saddle point is presented based on the linear response theory, in which the single particle spectra and wave function are provided by generalized Nilsson model. The dependence of viscosity coefficients γδ2δ2, γδ3δ3, γδ4δ4, γδ2δ3, γδ2δ4, γδ3δ4, on the collective variables δ2, δ3, δ4 is studied at various values of the nuclear temperature with the smearing width Γ=0.1hω0.
Using the resonant group equation and considering the limiting case of interaction tending to zero, we investigate the antisymmctric effect of nucleon and quark in scattering process quantitatively. The following results are obtained: (ⅰ) The antisymmetric effect is equivalent to a short range interaction, whose range is about the rms radius of scattering particle. (ⅱ) The smaller the rms radius of the particle is, the broader the distributed energy range of the antisymmetrie effect. (ⅲ) The more the freedom of the particle is, the weeker the equivalent interaction. (ⅳ) When the mean kinetic energy per nucleon in the incident nucleus is larger sufficiently than the kinetic energy of nucleon in the target resulted from the uncertainty principle, the antisymmetrie effect can be neglected.
Considering the time-dependent generator coordinate method, the time-dependent Schrodinger equation for nuclear collective motions is obtained. It is then possible to obtain through Wigner matrix a variational expression for mean collective properties q(t) and p(t) in classical limits. Under adiabatic approximation this is just the expression by which Villars has obtained the ATDHF results.
Quasi-elastic and deep inelastic reactions of 71.5 MeV 12C ions on a 27Al target are measured, ΔE-E telescope is used to identify the reaction products. The energy spectra, angular distributions and contour products in the E-θ plane are obtained and discussed.
According to SU(3) and the L-excitation Quark model, the Gs parity of strange mesons are evaluated. Suppose V-spin conservation, some selection rules in strong decay of resonance state of strange mesons are discussed.
Bassed on the "Rigid Projectile" approximation and the Glauber's multiple scattering theory. The influence of the nuclear short range correlation on elastic scattering of high energy heavy ion is discussed. The elastic α-12C scattering at 1.37 GeV is calculated and compared with experimential data. It is show that the influence of the unclear short range correlation on differential cross section is quite important.
In this paper we discuss the base state of initial and final states in the transition from the generating functional of quantum mechanics to that of field theory, i.e. the problem of vacuum state. This problem becomes more necessary, when we are interested in the structure of vacuum in gauge theory.
According to the principle of "Uniform magnetization", the field-shape of plane head quadrupole of "coil replacement" and "Quasi coil replacement" is analysed by means of series expansion. The magnetic field and gradient expression are given in the plane y=0. The optimization relations of height-width ratio of the magnetic piece are also presented.
The effect for the mixing of the three-band, the g, γ and β bands, on the i(ω) is discussed. The decreasing behavior for i(ω) after some value is interpreted, and it is shown that near the crossing point (ωc) of the s and g bands, rotation-aligned angular momentum of the quasiparticle is only a part of the total i(ω).
In this paper the particle-number-conserving method (PNC) for treating pairing correlations in deformed nucleus is extended to treat the spherical nucleus. The properties of the ground state and the lowlying 0+ states of even-even isotops nearby 208Pb are calculated with this method.
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