1992 Vol. 16, No. 3

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Identification of Primary Cosmic Ray Particles Producing Big Gamma-Families in Emulsion Chambers
REN Jing-Ru, LU Sui-Ling, SU Shi, HUO An-Xiang, WANG Cheng-Rui, HE Mao, CAO Pei-Yuan, LI Jin-Yu, WANG Shi-Zhi, LI Guang-Ju, BAI Guang-Zhi, LIU Zhong-He, MU Jun
1992, 16(3): 193-196.
The method of identification of primary cosmic ray particles of gamma families with visible energies above 800TeV has been investigated by using the results of Monte Carlo simulation.It has been found that,for proton primaries.the lateral distributions of certain parameters of gamma families may be taken as a reliable criterion.The experimental data of big gamma families obtained from Mt.Kanbala emulsion chamber experiment have been analyzed on the basis of this criterion.
Z0 Line Shape Fit
JIN Bing-Nian, XU Ya-Di
1992, 16(3): 197-201.
We state a fitting method of the Z0 line shape.We discuss the radiative corrections for calculating the theoretical cross sections of e+e→ff on Z0 resonance,and compare the results from different programs.The systematic measurement errors are taken into account in our fitting.As an example,we fit the τ+τ channel Z0 line shape to determine some Z0 parameters.
Effective topological action in Heisenberg spin model as Berry's phase
SUN Chang-Pu, PAN Lin, GE Mo-Lin
1992, 16(3): 202-207.
In this paper it is shown that the topologically additional action appearing in the Heisenberg spin model can be understood as a superposition of Berry's phases for the single spins in an average fields of many particles.In the case of low temperature,using the high order adiabatic approximation method,we obtain higher order corrections for this action.
The't Hooft Anomaly Matching condition in
XIAO Zhen-Jun, LU Gong-Ru, XUE Xiao-Zhou
1992, 16(3): 208-211.
In this paper one problem in H.Georgi's "MOOSE" model is discussed,and the necessity of 't Hooft anomaly matching condition for the confining phase theoretical analysis in Ri/j≈0 region is proven.
Spontaneous symmetry Breakdown and an Integral Expression of the Effective Potential in Quantum Electrodynamics
LI Fu-Bin
1992, 16(3): 212-218.
The functional formalism for the effective potential is briefly reviewed for the case of a scalar field theory by using the method of steepest descents.This formalism is then applied to quantum electrodynamics and an integral expression is derived for the effective potential in the one-loop approximation.This expression is used to verify the absence of spontaneous symmetry breakdown for quantum electrodynamics in one space and one time dimension.
Spin and parity analysis for the three-step two-body hadronic decay processes of J/ψ
SHEN Qi-Xing, YU Hong
1992, 16(3): 219-228.
The helicity formalism of the angular distribution for the cascade decay process e++e→J/ψ→V+X,X→P1+Y,Y→P2+P3 (V represents a vector meson and Pi(i=1,2,3) are the pseudoscalar mesons) is presented in this paper.It provides the theoretical formulas for the spin-parity analysis of the intermediate state X through a three-step two-body hadronic decay processes of J/ψ.
A Test of the α-Particle Structure of 16O by Means of the Proton Scattering
LI Qing-Run, ZHOU Jin-Li
1992, 16(3): 229-234.
The α-particle model for 16O is tested by means of the proton scattering.The elastic angular distributions for the proton-16O scattering ranging over the whole intermediate energy region are calculated without any adjustable parameter.A overall agreement between the theoretical results and experimental data is obtained.
The two Normalization schemes of Factorial Moments in High Energy Collisions and the Dependence Intermittency Degree on Average Transverse Momentum
WU Yuan-Fang, LIU Lian-Shou
1992, 16(3): 235-240.
The two different normalization schemes of factorial moments are alalyzed carefully.It is found that in both the cases of fixed multiplicity and of intermittency independent of multiplicity,the intermittency indexes obtained from these two normalization schemes are equal to each other.In the case of non-fixed multiplicity and intermittency depending on multiplicity,the formulae expressing the intermittency indexes from the two different normalization schemes in terms of the dynamical index are given.The experimentally observed dependency of intermittency degree on transverse momentum cut is fully recovered by means of the assumption that intermittency degree depends on average transverse momentum per event.It confirms importance of the dependency of intermittency on average momentum.
Color Screening Effect and Spectrum of Baryon
YANG Hua, DENG Wei-Zhen, ZHANG Zong-Ye
1992, 16(3): 241-249.
A confinement potential which obtained from the lattice-gauge-theory has been used to study the spectrum of baryon and the rms of the quark distribution.
Study on the Correlation between Projectile-Like Fragments And α-Particles in 20Ne (14.7,19.2MeV/u)+58Ni Reactions
HU Xiao-Qing, ZHU Yong-Tai, SHEN Wen-Qing, LI Song-Lin, ZHAN Wen-Long, XI Hong-Fei, ZHU Xiang, ZHANG Zhen
1992, 16(3): 250-255.
The coincidence between projectile-like fragments and α-particles emitted from 20Ne(14.7,19.2MeV/u)+58Ni reactions has been studied.The coincident events were caused by the sequential decay of the excited primary fragments and by the "uncorrelated" coincidence between forward emitted α-particles and projectile-like fragments,formed in a deeply dessipated reaction process,as well.This reaction process means,that the α-particle flied off from the 20Ne projectile in the initial stage of the reaction,and then the residual 16O collides with the target nucleus dissipatively.It is called "Incomplete Deep Inelastic Process".
Comparison Between IBM and BMM;the Continuous Variables Representation Under the low Excitation Approximation
LIANG Shi-Dong, FU De-Ji, XU Gong-Ou
1992, 16(3): 256-265.
By using the generator coordinate method approach to the dynamic group represenation (DGR-GCM),the continuous variables representation of IBM is obtained under the low excitation approximation and is compared with BMM.Not only the relation between the mean field and the dynamical symmetry has been analysed but the spherical nuclei as well as deformed nuclei have been discussed in an unified way.The accuracy and available extent of the continuous variables representation is demonstrated by means of analysing the potential surface and the spectra of Gd isotopes.The results have been compared with the experimental data and the algebraic solution of IBM (PHINT CODE).
Coriolis Attenuation Effect on the Bandcrossing Frequency of 164Er96
LIAO Bo-Qin, LIN Xin-Wei
1992, 16(3): 266-271.
The accurate solutions to the low-lying eigenstates of the cranked shell model Hamiltonian are obtained by the particlenumber-conserving treatment,in which Coriolis attenuation is considered.Compared with experiments,the results are much better than before.
Intrinsic Condensate Method for Microsopic IBM2 and Calculation of 168Er Spectrum
DENG Wei-Zhen, YANG Ze-Sen
1992, 16(3): 272-277.
By the intrinsic condensate method,an attemption is made to cancel the maximum F-spintruncation approximation usually adopted in IBM2.In the region of deformed nuclei,the intrinsic condensate and is intrinsic excitations are used to describe the low-lying collective rotational states.Using this method.the low-luing spectrum of 168Er are calculated.The result show that the maximum F-spin truncation approximation become bad for the excitational bands,and the intrinsic excitations of neutron boson and proton boson are mutual separated.
Calculating on Wavefunctions of the Ground State Band for the Strong Coupling SU(3) Limit in IBM4
LI Guang-Hua, HE Hui-Yong
1992, 16(3): 278-284.
Using the group theoretical method,the wavefunctions of intrinsic states for the strong coupling SU(3) limit in IBM4 are given.Then,the wavefunctions of ground states band are obtaind from the above wavefunctions by a projection method.
Shuttle Acceleration Mechanism of Nucleons in hi Reactions
HO Yu-Kun, YUAN Zhu-Shu, PAN Zheng-Ying
1992, 16(3): 285-288.
This paper studies a mechanism of acceleration of high-energy nucleons in intermediate and high energy nucleus-nucleus collisions,where a part of the projectile nucleons undergo alternating shuttle collisions between the target and the rest of the projectile,and successive accelerations.Preliminary calculations based upon a classical picture indicate that an energy boost of 0.33E0 can be generated after once shuttle collision,E0 is the mean incident energy per nucleon.The energy spectra and angular distributions of emitted nucleons are evaluated,and the physical significances of the results are discussed.