1983 Vol. 7, No. 1
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The yields and energy spectra of the various components of o-Ps annihilation in silica aerogel are observed using the combined spectrometer. It is shown that the processes of Ps formation and annihilation in ultrafine grains of SiO2 aerogel are basically consistent with the diffusion model, but the grain surface effect can not be neglected. Comparing the Dopplar broadening spectra, it is understood that the pick-off process of the longest component possesses the lower annihilation momentum than that of the free positron annihilation.
Using the analytic expression for valence quark distribution function of hadron in the leading logarithm approximation given by paper, we discuss the QCD behaviour for the valence quark distribution function of pion. The existing data for valence quark distribution function of pion are explained excellently. We also predict the differential cross section M3 dσ/dM for massive lepton pairr production with Drell-Yan mechanism and compare it with data.
In this paper we propose an SU(4)×SU(2)×U(1) unified model, in which the stratons and leptons of every generation belong to the same Multiplet, and the leptons will couple to the stratons. But this kind of coupling cannot cause the proton decay, and has only some effects in high energy scatterings. This model predicts the existense of two neutral intermediate bosons, instead of one, and the value of Weinberg angle to be sin2θw=0.25. The neutrinos have reasonable masses in the model.
According to the idea of reference  for solving light-fermion mass hierarchy problem, all possible SU(9) grand unified models are systematically examined. The conclusion is negative, there is no hope to realize (α2,α,1) pattern in SU(9) models.
Using the B-S wave functions of mesons in the massive straton model, we discuss their weak decay, electromagnetic decay, and particularly hadronic decay processes. Not only fπ≈fK, 1－→l+l－ rate are successfully explained, the predicted widths for various hadronic decays are also in good agreement with experimental data.
The Prasad-Sommerfield-like, colorless anl finite-mass dyon anolytic solution in SU(5) ground unified model is found. It is the only physical dyon solution so far. In the SU(5) model the Dirac equation of fermions in the dyon field is derived concretely, and the mathematic method for solving the equation is pointed and discussed.
In this paper, the principle of adjusting the proton energy from the linear accelerator with energy adjusting cavities is proposed. The requirements to energy adjusting cavities for tuning the proton energy efficiently and continually are studied. The energy range adjustable and the energy spread are calculated for 35 MeV proton linac which is in the course of construction at the Institute of High Energy Physics, as an example. The energy spread as a function of electric parameters of energy adjusting cavities are also discussed. A specific and economical method to supply rf power to energy adjusting cavities is presented.
In this paper, the relations among objects, images and beam waists for charged particle beams are studied. On this basis, the relations between geometrical electron optics and beam transport theory are discussed.
In this paper, how to extend the baryon unitary theory to the baryon system is systematically introduced. Using baryon-system SU(6) theory, the spectroscopy of light nuclei and light nuclei and light Λ hypernuclei is discussed. When the Λ degree of freedom is frozem, this theory is in agreement with Wigner's supermultiplet theory.
In this paper, a folded diagram method for deriving an energy-independent nucleon-nucleon (N-N) potential from meson exchanges is proposed. The potential obtained by this method contains not only the irreducible diagrams but also the mesonic folded diagrams. And it is proved that all stretched diagrams are not contained in this potential.
The binding problem of isobar Δ(1232) in 4He 12C and 16O systems is studied in detail by Hartree-Fock method. The OBEP is used for the nucleon-nucleon potential and the nucleon-Δ(1232) interaction. The calculated results show that Δ(1232) can be bound only in 4He and not in 12C and 16O systems.
The energy spectra and angular distributions of α-particle emitted from 12C-induced reactions with 159Tb, Ag and 89Y targets have been measured. Meanwhile the emitted deutron's angular distributions with 159Tb and 89Y targets and proton's with 89Y target have been also obtained.
The α-energy spectra associated with mentioned reactions have bell-like shape with probable energy near coulomb barrier. However, the main characteristic of the α-angular distribution for 159Tb and Ag targets is peaked at or near the grazing angles. For the case of 89Y target, α-differential cross-sections monotonically decrease with angles beyond 40º. The angular distributions of potons and deutrons nearly decrease exponentially.
The measured α-angular distributions could be divided into two components, one coming from α-evaporation is isotropic, another is anisotropic. The anisotropic component may be explained incomplete-fusion process in which the cross-section can be reproduced by a "Sum-Rule Model" due to J.Wliczynski.
In order to explain the anisotropic component of emitted α-particle, we propose in complete fusion model with a strong-damped sticking rotation, in which the rotation angles and interaction time of the composite system are also estimated.
The method of parametrization of EFR-DWBA overlap integral developed by T.Udagawa and T.Tamura et al., is improved. Using the improved method we have fitted the experimental double differential energy spectrum of 8Be-cluster coming from the reaction 208Pb (12C, 8Be) 212Po leading to the continuum states and extracted the preformation probability of α-cluster at the surface of 212Po nucleus. Within the range of calculation error, the result is in agreement with that extracted from fitting the experimental data of α-decay.
It is shown that without exception the observed rms charge radius constants of strongly deformed nuclei, rp's, are a little larger than those of the neighbouring spherical nuclei. The local variations among the charge radii of the sequence of isotopes, the in complete neutron shells [1p3/2(N~3—6), 1d5/2(N~9—14), 1f7/2(N~20—28), 1g9/2(N~40—50), 1h11/2(N~70—82)], display some peculiar behaviors (eg. rms cnarge radii decrease with increasing A) which are sharply conflicting with the traditional A1/3 law. Taking the deformation effect into account, these strange variations can be accounted for with the Z1/3-law.
In this paper, using SU(6) symmetry theory four-baryon system is discussed and a method of analyzing experimental spectra is provided. Because of the gound states of ΛΛ4H, ΛΛ4He, Λ4He and 4He are in the same I. R. of SU(6), on can derives masses for ΛΛ4H, ΛΛ4He from the experimental data of Λ4H, Λ4He, and 4He. Calculation shows that these Jπ=0+ double Λ hypernuclei ΛΛ4H, ΛΛ4He are not likely bound states.
In present paper, the applications of N0,the number of atoms of a certain radioactive isotope in a target at a given time t0 (usually the end of a bombardment by incident particles) in the measurement of the reaction cross section or the beam intensity or in the activation analysis are discussed and the accuracy of N0 (also the cross section) is analyzed.
Intensities of ultrahigh energy γ-rays observed in Chinese emulsion chamber experi ments at several altitudes, including Yunnan Station (3200 m), Mt. Kambala (5500 m), and the foot of Mt. Qomolangma (Everest, 6500m) are summarized. An intensity altitude relation and in particular, the attenuation length of γ-rays at the foot of Mt. Qomolangma are presented.
In this note, we have given a method of calculating the transformation coefficients between SO(6) and SU(4) Gelfand Zetlin states.
We have first developed a new kind of particle detector using petrolic gas, which is based on the SQS (Self-Quenching Streamer) discharge mode. It is possible to save a lot of money if this kind of detector will used as some elements of high-energy spectrometer at electron-positron collider or other kinds of high-energy accelerators.
It is possible to use this kind of detector to low-energy Nuclear technology, health physics and environment protection regions, too.
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