1988 Vol. 12, No. S1

Display Method:          |     

Xian Dingchang
1988, 12(S1): 0-0.
Dependence of 丨nteraction Cross Sections of High Energy Cosmic Ray Iron Nuclei (E≥3.6A GeV) on Atomic Weight of Targets
Ren Guoxiao, Zhou Yinzao, Huang Rongqing
1988, 12(S1): 1-8.
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.
A Phenomenological Model for Positron Trapping at Dislocations
Xiong Liangyue
1988, 12(S1): 9-18.
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.
The 250 MeV Section of BEPC 1.1/1.4 GeV e± Linac
Electron Linac Laboratory
1988, 12(S1): 19-26.
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.
On the Hermitian of Hamiltonians of Radial Equations
Ma Zhongqi, Dai Anying
1988, 12(S1): 27-36.
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.
Multinucleon Effect in the Pion Single Charge Exchange Reaction
Chen Kezhong, Jiang Huanqing
1988, 12(S1): 37-44.
Under the frame of DWBA, using multinucleon effects in transition matrix elements and optical potential, we calculate the 13C(π+0) 13N(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.
Charge Dispersion of Fragments in High Energy Proton-Nucleus Collisions
Lu Zhaoqi, D. H. E. Gross, Sa Benhao, Zheng Yuming
1988, 12(S1): 45-50.
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.
The Mass Gap in 2 + 1 Dimensional SU(2) Lattice Gauge Theory
Zheng Weihong, Liu Jinming, Guo Shuohong
1988, 12(S1): 51-54.
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/g2 ≤ 7, a good scaling behaviour am = 2.28g2 is obtained, which is in agreement with weak-coupling expansion result.
Studies of ρ and K* Mesons Decay by the One-Gluon-Exchange Quark-Antiquark Pair Creation Model
Yu Youwen, Sheri Pengnian
1988, 12(S1): 55-58.
Decay rates of ρ-meson into two π-mesons and K* into Kπ mesons are calculated by using the one-gluon-exchange quark-antiquark pair creation model. The results agree with the experimental data.
Down-Quark Masses and Flavor Mixing
Jin Changhao
1988, 12(S1): 59-68.
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.
New Infinite Symmetries in the Stationary, Axially Symmetric Einstein-Maxwell Fields
Hou Boyu, Li Wei
1988, 12(S1): 69-76.
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.
Baryons as Solitons in a Non-Linear a Model With Only a Sixth-Order Stabilizing Term
Wen Jiaru, Huang Tao
1988, 12(S1): 77-80.
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 Fπ and the axial coupling constant gA are all better improved in this model.
Nuclear Pairing Phase Transition
Wu Chongshi, Zeng Jinyan
1988, 12(S1): 81-90.
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.
Alpha-Correlation in a Single-Level Model
Ren Zhongzhou, Xu Gongou
1988, 12(S1): 91-98.
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.
Mass Distribution in the 14.7 MeV Neutron-induced Fission of 232Th
Sun Tongyu, Li Wenxin, Dong Tianrong, Fu Ming
1988, 12(S1): 99-107.
The yields are determined for 57 fission prcxJucts from 77gGe to 151Pm in the 14.7 MeV neutron-induced fission of 232Th 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.