1985 Vol. 9, No. 5
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The apparatus consisting of two time of flight systems and absorber and its performences are described. This apparatus has been used to measure heavy particle (p, d, and α) mass distribution in cosmic ray at sea-level, and the results compared with other works are given.
The correlation of forward-backward multiplicities about 9×104 events under minimum-bias trigger condition of UA-1 experiment on 540 GeV proton antiproton collider at CERN is reported. Different cut-off condition and different acceptance correction methods of UA-1 central detector are selected in order to obtain flater rapidity distribution. The correlation strength of short, long, full, and fragmentation range is given. Correlation between regions which are symmetrical and unsymmetrical to the plane with axial angle θ=90° is discussed. The correlation strength in short range forward-backward regions with equal charge is compared with that of opposite charge. All results are compared with other works and with some theoretical models.
The exact formula set for the midplane of the uniform-field wedge magnet is derived. The calculations include input and output wedges and curved surface on the input and output faces. The applications of the exact formula set in some cases are discussed.
The vertical differential momentum spectrum and the charge ratio of the cosmic ray muon, in the range(0.4—250GeV/c), has been measured by means of the magnetic spectrometer and the range-spectrometer in Yunnan station at 3200 m above the sea level. The present spectrum is in agreement with the differential spectrum of muons, measured by others at the same mountain altitude. In the 15—250GeV/c momentum range, the spectrum obtained from the present experiment is also in good agreement with the differential spectrum of the muon which has been determined by O.C. Allkofer et al. at the sea level. The charge ratio of the muon is almost constant in the range (5—100GeV/c). The average value is 1.30±0.06.
We propose a composite model of leptons and quarks containing two constituent fermions of spin 1/2 and a constituent scalar. The constituent fermions are massless and color singlets. Leptons, quarks and weak vector bosons are composites confined by SU(3)H local gauge interaction, where leptons are made of three constituent fermions and quarks are two-body composites of a scalar and a fermion. The number of the constituent particles is less in our model. There are less exotic leptons and quarks. Quark-lepton parallelism holds. Weak interactions appear only at the composite level as residual short-range interactions among hypercolor singlets. The violation of parity occurs by the mechanism of dynamical symmetry breaking.
In this paper we discuss the SU(3) limit of U(6/20) supersymmetry. First we derive the reduction formulas of the relevant group chain. Then we discuss the dynamical symmetry. Finally we make comparison between the theoretical calculation and experimental measurement in the case of nucleus .23592U143
In this paper we disscuse disscuse the physicsical aspect of cross-section differences ΔABcγ=dσ(AB→cγX)-dσ(AB→cγX) and give the simple rules to select the elementary subprocesses which contribute to cross-section differences.
We bind a way to test the gluon distribution functions of hadrons through the measurement of cross-section difference or combination of cross-section differences in the large PT process with direct photon emission. Moreover we obtain simple relations between each combination of cross-sections and the corresponding gluon distribution functions of proton, neutron, pion and daon:
Gp8(x)/(Δpphγ－Δpphγ)=Gn8(x)/(Δpphγ)=Gπ8(x)/(Δπ+phγ+Δπ－phγ=GK8(x)/(ΔK+phγ+ΔK－phγ)which are expected to be test in experiment.
The heavy-ion collisions are studied by means of two-component Fokker-Planck equations on the assumption that there exist multiquark states in nuclei. Inclusive cross section for the production of p is calculated in heavy-ion collisions of C+C, Ne+NaF and Ar+KCI at 800 MeV/N; Ne+NaF at 400 MeV/N, 800 MeV/N and 2100 MeV/N. A satisfactory agreement with the experimental data near c.m. 90 degree is obtained. The production of d in the collision of C+C at 800 MeV/N is also discussed.
We discuss the possibility that the new particle ξ(2.22) is a mixed state of the Higgs boson of the minimal electro-weak model and the p-wave charmonium χ(3.415). If this possibility stands, we shall have Γξ=1.1 keV, Br(ξ→K+K－)～1/5 and a heavy quark (m>75GeV).
We calculate the differential cross section of α-α elastic scattering with the complete expansion formula of the Glauber amplitude of high energy nucleus-nucleus elastic scattering and the rigid projectile approximation. The results are satisfactory.
In this paper, the average luminosity of linac injected electron positron collider is investigated from the positron-producing energy point of view. When the energy of the linac injector is fixed to be less than the operating energy of the storage ring, it has been found that there exists a positron-producing energy to give optimum average luminosity. Two cases have been studied, one for an ideal storage ring with no single-beam instability and the other for practical storage ring with fast head-tail instability. The result indicates that there is a positron-producing energy corresponding to the minimum injection time, but this does not correspond to the optimum average luminosity for the practical storage rings. For Beijing Electron Positron Collider (BEPC), the positron-producing energy corresponding to the optimum average luminosity is about one tenth of the total injector energy.
The low-lying levels of 18O and 18F have been calculated using several Skyrme interactions and the many-body folded diagram theory of Kuo, Lee and Ratcliff. Our results obtained with the Skyrme interactions determined by Vautherin and Brink and by Krewald are not in satisfactory agreement with the experimental spectra.
On the basis of Yukawa folded density distribution, a new formula of nuclear charge radius is proposed to include the effect of both spheroidal and tetroidal deformation. With the values of only two constants, the resulting root-mean-square error in calculated nuclear radii of 148 nuclides is 0.034 fm, which is near to that of Droplet model. It can be used to explain the nuclear radii of some isotopic sequences where the Z1/3 law has difficulties. Taking the fluctuation of diffuseness width into account, the peculiar behaviors of some isotopic sequences can be well explained. The dependence of all the fluctuation on the neutron shell structure is also discussed.
The role of the non-diagonal difusion coefficient D12 of the two dimensional F-P EQ. In the mean value of angular momentum of fragments, their varaince and covaraince are discussed. It is found that D12 doesnot influence the equilibrium value of the quantities, but influences the rate for the quantities to reach equilibrium. So that it mainly influences the angular momentum transfer at the beginning of the reaction and that of large incident angular momentum partial waves. We also find that the covaraince is especially sensitive to D12.
The decreasing coefficients of the angular distributions, the charge distributions and the first and second moments of the charge distributions with variation of TKEL are deduced from the results of the measurement of projectile-like fragments produced by 80.6MeV 16O on 27Al. The relaxation process of this reaction is analysed, the effects of the potential energy surface on the first and recond moments of charge distributions are discussed.
The central and two body spin-orbit coupling forces as the residual interaction and the pure configuration are used to calculate the energy spectra of 1f7/2 shell nuclei (43Sc,44Ti,52Fe,53Fe,53Co) with nonidentical configuration. The consistency bettween the calculated energy spectra of the nuclei and the experimental data are rather satisfactory.
A shape, rotating cassin's oval body with symmetry deformation parameter of 1.0, in nuclear fission scission point is suggested. By use of the shape, simple calculations on average total kinetic energy of fission fragments in both symmetry and asymmetry cases show that the results are in agreement with semiempirical formula due to V.E. Viola.
(1) Martin's theorem about the wave function at the origin is extended to the states with l≠0. (2) The theorems about energy levels between 2s, 2p, 3d states are extended to 3s, 3p states to the first order of perturbation.
A variational method based on Hölder integral inequality is presented. Taking the parameters in integral inequality as variational parameters, we can calculate the free energy in lattice gauge system. The plaquatte energy of Z2 、U(1)、 SU(2) gauge system is found and consistent with that given by Monte Carlo method. But, the higher phase transitions for U(1), SU(2) gauge systems are not found.
The preliminary results of big family events obtained by emulsion chamber experiment at Mt. Kanbala are presented. General feature of γ-ray familes with ΣEγ≥1000TeV are discussed and compared with the Monte Calo simulation.
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