## 1988 Vol. 12, No. S1

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**Abstract:**

Using plastic nuclear track detector CR-39 interleaved with various targets， nucleus-nucleus interaction cross sections of high energy Fe nuclei (E≥3.6AGeV) with C, Al, Fe and Cu nuclei at balloon level in Beijing area were measured and the dependence of interaction cross sections on the atomic weight of targets was obtained.

**Abstract:**

A multi-state trapping model involving positron trapping at dislocations and jogs is proposed, in which effect of positron detrapping can be omitted. According to this mcxJel the dislocations with variant jog density have different functions in positron annihilation process. The case that dislocation trapping is predominant and the open-space ratio between dislocation core and singlevacancy is emphatically discussed. Using the data in some literatures, we have estimated the positron annihilated rate at dislocations and the jog interval on the dislocation line. The results obtained seem reasonable.

**Abstract:**

The beam test of the 250 MeV section of the BEPC 1.1/1.4 GeV e

^{±}linac was performed four times during its installation phase. In May 1987, an electron beam of 760 mA and 250 MeV was obtained and a positron beam of 2.5 mA and 99 MeV was observed when an electron beam of 785 mA and 150 MeV bombarded a tungsten target. The main parameters of the linac have met the designed goal and reached the same technical level of similar accelerators in other countries.

**Abstract:**

The Hamiltonian of a radial equation is defined on a half-line, and there is an intimate relation between its hermitian and the boundary conditions of the wave functions at the origin. If the wave functions are nonvanishing and convergent at the origin, the Hamiltonian has a one-parameter family of self-adjoint extensions which are related to the condition for the vanishing radial probability current at the origin. In this paper the problem on the hermitian of the Hamiltonian of a radial equation is studied systematically. Some methods for determining the parameter for the fermion moving in a magnetic monopole field are discussed.

**Abstract:**

Under the frame of DWBA, using multinucleon effects in transition matrix elements and optical potential, we calculate the

^{13}C(π

^{+},π

^{0})

^{13}N(IAS) reaction and study the angular distribution at 165 MeV, the forward angle excitation function and the integrated cross section in this reaction. A formula for the mass dependence of the forward differential cross sections is derived.

**Abstract:**

In this paper the authors calculate the charge dispersion of fragments in high energy P + Cu, Kr and Xe reactions by statistical model and Monte Carlo tech-nique.and the results agree with the experimental data. It shows that all charge dispersions are displayed in Gaussian. The mass dependence on the most probable charge of fragments reflects some memory effects in residual targets.

**Abstract:**

A glueball mass in 2 + 1 dimensional SU(2) lattice gauge theory is calculated by applying variation in the Hamiltonian with exact ground state. In the range 0 ≤ 1/g

^{2}≤ 7, a good scaling behaviour am = 2.28g

^{2}is obtained, which is in agreement with weak-coupling expansion result.

**Abstract:**

Decay rates of ρ-meson into two π-mesons and K

^{*}into K

_{π}mesons are calculated by using the one-gluon-exchange quark-antiquark pair creation model. The results agree with the experimental data.

**Abstract:**

The paper proposes a parametrization of KM mixing matrix based on the regularities of the matrix shown in experiments, discusses some physical im-plications of new parameters. Within quark weak interactions a phenomenological constraint of the down-quark mass matrix is obtained. The author also suggests a model of the down-quark mass matrix,with which the KM mixing matrix elements can be estimated using down-quark masses. The results agree quite well with experimental data.

**Abstract:**

We generalize the infinitesimal transformations previously obtained in the vacuum Ernst fields to the one with electromagnetic fields,and recieve a larger infinite symmetric group which is isomorphic to the Virasoro group without central term. A subgroup of the new symmetric group, namely the enlarged Cosgrove group, is found. A new solution of electromagnetic fields can be generated from old ones by our transformations.

**Abstract:**

We treat baryons as solitons and compute their static properties in the SU(2) × SU(2) non-linear σ model which contains merely a sixth-order term to stabilize soiitons. To compare with Skyrme mcxiel, the prediction values we obtained，especially the pion decay constant F

_{π}and the axial coupling constant g

_{A}are all better improved in this model.

**Abstract:**

The intrinsic structure of the eigenfunctions of Cranking Shell Model Hamiltonian and the pairing phase transition at high rotational frequency are investigated with the particle-number-conserving approach. Pair-transfer matrix elements and the K-stojcture of the wave functions display similar behaviour under the Coriolis interaction, hence, both of them may be used to indicate the pairing phase transition. The blocking effects on pairing parameter, △ = G√< S + S >, are much more important than the Coriolis anti-pairing effects.

**Abstract:**

The α-correlation in a single-level model with pairing forces independent of spin and isospin is discussed in this paper. The analytical solutions to this problem are obtained by using the Boson-Fermion representation. The paper also provides analytical expressions for the α-correlation energy and reduced rate of α-transfer and discusses the significance of the obtained results.

**Abstract:**

The yields are determined for 57 fission prcxJucts from

^{77g}Ge to

^{151}Pm in the 14.7 MeV neutron-induced fission of

^{232}Th by

*γ*-ray spectrometry and chemical separation followed by 7 -ray spectrometry. From these data, the total chain yields for 44 mass numbers are obtained in which 12 chain yields are presented for the first time. The yields determined in this paper are compared with all published literature values.

**ISSN** 1674-1137 **CN** 11-5641/O4

Original research articles, Ietters and reviews Covering theory and experiments in the fieids of

- Particle physics
- Nuclear physics
- Particle and nuclear astrophysics
- Cosmology

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