1989 Vol. 13, No. 4

Display Method:          |     

Review
ON-LINE TESTING OF 8 TUBE MUON MODULE FOR BEIJING SPECTROMETER
GAO Wen-Xiu, LIN Shu-Zi, XU Zhi-Qing, SHEN Ben-Wei, FANG Cheng, GU Shu-Di, WANG Pei-Liang, HU Jia-Sheng
1989, 13(4): 289-292.
Abstract:
A brief description of muon identifier for BES was given.The on-line tesing results of a 8-tube muon module with electronics show that both the muon module and the electronic system are stable and satisfy the requirements of muon identifier:good linearity,about 250V plateau,standard deviation of charge division <3cm and padestal walk of electronic system is about ±1 channel.
A TRIGGER SCHEME FOR COSMIC RAY EXPERIMENT WITH A SAMPLE-AND-HOLD SYSTEM
HAO Wei, LU Chang-Guo, QUE You-Kun, ZHOU Yue-Hua
1989, 13(4): 293-297.
Abstract:
This paper presents a trigger scheme which has been used in a cosmic ray experiment with a sample-hold readout system.The experiment shows that this trigger scheme can fully collect the whole output signals of the wire chamber for the random cosmic ray events and get rid of the problem of signal loss caused by the delay of sampling gate.Some disscussions about using this scheme for cosmic ray test of BES are also provided.
ELECTRON CLOUDS IN AXIAL SYMMETRIC SPACE-CHARGE LENSES
YU Qing-Chang
1989, 13(4): 298-301.
Abstract:
The focusing properties of a space-charge lens depend on the size,shape and density distribution of its electron cloud.In this paper these parameters are discussed by both numerical and analytical methods.
THE EQUIVALENCE OF TWO TRANSFORMATIONS OF THE INVARIANCE OF LAGRANGIAN FUNCTION IN NON-ABELIAN GAUGE FIELD
QIU Rong
1989, 13(4): 302-308.
Abstract:
In this paper,the general transformation of non-abelian gauge field is derived from the in variance reguirement of the effective lagrangian function.It is shown that when the group parameter θ(x) is the product of the anti-commuting ghost field and an infinitesimal number anticommuting ξ which is independent of the component indices space,the B.R.S.transformation is obtained.When θ(x) is equal to the ghost field C(x) times an infinitesimal tensor ξi which is commuting with respect to the upper index b,we get another transformation.Both transformations are proved to be equivalent.
GAUGE TRANSFORMATION IN STRING THEORY
LU Jian-Xin, RUAN Tu-Nan
1989, 13(4): 309-315.
Abstract:
In this paper,the authors find a transformation which connects the covariant formalism with the light-cone formalism in bosonic open string theory,which leads to the connection between covariant statevectors and light-cone statevectors,and yields an orthogonal complete set of states in covariant formalism and a physical projective operator for arbitrary space-time dimension D and intercept of Regge trajectory α(0).The later reduces to the result given by L.Brink and D.Olive in the case of D=26,α(0)=1.Finally,we explicitly show that in covariant formalism,the mass square operator M2≥0 except for the tachyon of ground state.
THE MC CALCULATION OF MASS GAP IN 2+1 DIMENSIONAL SU(2) LATTICE GAUGE THEORY
LI Zhi-Bing, ZHENG Wei-Hong, GUO Shuo-Hong
1989, 13(4): 316-319.
Abstract:
By combining Monte Carlo method and variational method,we calculate the mass gap of SU(2) lattice gauge theory in 18*18 lattice of 2+1 dimensions by means of the icosaheral subgroup (Y120) using a hamiltonian of which the ground state is exactly known.In the range 0<1/g2,we obtain the results which are in good agreement with analytical calculation of SU(2) group.The scaling behaviour of mass gap am=2.3g2 is confirmed.
INFINITE CONFORMAL SYMMETRIES AND RIEMANN-HILBERT TRANSFORMATION IN SUPER PRINCIPAL CHIRAL MODEL
HAO San-Ru, LI Wei
1989, 13(4): 320-327.
Abstract:
This paper shows a new symmetric transformation——C transformation in super principal chiral model and discover an infinite dimensional Lie algebra related to the Virasoro algebra without central extension.By using the Riemann-Hibert transformation.The physical origination of C transformation is discussed.
VACUUM OF 2+1 DIMENSIONAL SU(2) LGT WITH FERMIONS AND SPONTANEOUS CHIRAL SYMMETRY BREAKING
LUO Xiang-Qian, CHEN Qi-Zhou, GUO Shuo-Hong
1989, 13(4): 328-333.
Abstract:

By incorporating the exact ground state of pure gauge theory and the variational fermion vacuum state,the vacuum structure of 2+1 dimensional SU(2) LGT with fermions is studied.We calculate the fermion condensate <ψψ>,and obtain a good scaling behavior.

THE BKS DERNEL OF BOSONIC STRINGS AND PATH INTEGRAL
FEI Shao-Ming, YU Yue
1989, 13(4): 334-338.
Abstract:
The connections between geometric quantization and path integral quantization of bosonic strings are investigated.The Polyakov path integral formulation and its measure are manifestly deduced from the Blattner-Kostant-Sternberg(BKS) kernel of geometric quantization.
IMPROVEMENT OF THERMODYNAMICAL MONTE CARLO SIMULATION IN SU(2) PURE GAUGE FIELD THEORY ——AN APPROACH TO CONTINUUM PHYSICS LIMIT
ZHU Zheng-Kun, ZHANG Xiao-Ze, JIN Xing-Nan, SA Ben-Hao
1989, 13(4): 339-345.
Abstract:
The thermodynamical quantities of SU(2) pure lattice gauge field have been simulated first time on the asymmetric lattice (ξ>1).The finite size effect and continuum physics limits have also been studied.The results show that the use of asymmetric lattice is of benefit to calculate the thermodynamical quantities and study the behavior of continuum physics limits.In addition,it is explained that the efficiency of the whole Monte Carlo simulation and the calculation of heat capacity will be improved quite a lot by using bias sampling technique.
STUDY OF COLLECTIVE SPECTRUM FOR 157,159Tb AND 155,157Gd
LIU Yong, SANG Jian-Ping
1989, 13(4): 346-352.
Abstract:
A microscopic approach for studying the collective states of odd-mass nuclei is proposed from the viewpoint of interacting boson-fermion model Hamiltonian is derived and used for calculating the spectrum of 157,159Tb and 155,157Gd isotopes.Numerical results are it qualitative agreement with experiment.
THE CROSS SECTION MEASUREMENT FOR THE 107Ag(n,2n)106mAg REACTION
WANG Hua-Min, WANG Yong-Chang, YUAN Jun-Qian, WANG Xue-Zhi, REN Zhong-Liang
1989, 13(4): 353-356.
Abstract:
The cross section for 107Ag(n,2n)106mAg has been measured by using the activation method relative to the cross section of 27Al(n,α)24Na in the neutron energy range of 13.50—14.73MeV.The values of 469±22,480±22,503±24,538±25,555±25,572±26mb were obtained at the 13.50,13.60,13.90,14.10,14.35,and 14.73MeV neutron energy,respectively.The results are compared with the published data.The neutron energies were determined by activity ratios of Nb and Zr foils.
APPLICATIONS OF THE MODIFIED SURFACE DELTA INTERACTION IN THE ANGULAR MOMENTUM PROJECTION DEFORMED HAREE-FOCK METHOD
LIAO Ji-Zhi
1989, 13(4): 357-361.
Abstract:
In this paper a modified surface delta interaction with an angular momentum correction term is proposed.By using this interaction the deformed Hartree-Fock and the approximate angular momentum projection calculations are performed for even-even nuclei in mass region A=56—74.The single particle energy spectra of the ground state configurations obtained are more reasonable than that calculated with KB matrix elements.The agreement of the calculated binding energies and projection energy spectra with experimental ones is fairly good.
ON THE VALIDITY OF THE CHFB METHOD FOR TREATING THE CSM HAMILTONIAN
PENG Jian-Ping, WU Chong-Shi, ZENG Jin-Yan
1989, 13(4): 362-369.
Abstract:
The accurate solutions for the low-lying eiginvalues and eigenstates of the single-j CSM hamiltonian have been obtained and are compared with the HFB approximation.There exist a world of difference between the two,especially the behaviour of the yrast and the yrare bands near the bandcrossing and the band interaction strength.The theoretical foundation of the CHFB method for treating the rotating nuclei needs reexamination.
MICROSCOPIC ANALYSIS OF THE LOW-LYING EVEN PARITY BANDS IN 168Er
HUANG Hai-Xin, WU Chong-Shi, ZENG Jin-Yan
1989, 13(4): 370-379.
Abstract:
Taking into account the pairing correlation plus the quadrupolequadrupole interaction,the intrinsic properties of the low-lying bands (even parity) and the related E2 transition probabilities in 168Er were calculated in the frame of Bohr-Mottelson-Nilsson model.The agreement between the calculated and the observed results is satisfactory.Some difficulties encountered in the IBM prediction do not appear in the present calculation.
CALCULATION OF THE EFFECTIVE MOMENT OF INERTIA OF FISSIONING NUCLEI AT SADDLE POINT
CHEN Xin-Yi, HU Ji-Min
1989, 13(4): 380-383.
Abstract:
The effective moment of inertia,charge density distributions of the fissioning nucleus 170Yb and 254Fm at saddle point are calculated by using the continuous medium model with variable densities.