1994 Vol. 18, No. 10
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The dependence of longitudinal momenta of secondary charged particles produced in non-diffractive processes of pp collisions on the multiplicity at s=540GeV has been analyzed by using a Monte-Carlo generator of full Chou-Yang geometrical model.The results show that the average longitudinal momentum of secondary particles becomes larger and their x -distribution flatter when the multiplicity of secondary particles decreases.
Radiation hardness properties of calorimeters with different structures or different materials used for the tile/fiber were studied.Ten calorimeter modules were irradiated by the BEPC electron beam(1.1 or 1.3 Gev).Radiation damage is quantified by measurements of the light yields in various locations within the calorimeter modules at different integrated doses.We also studied the recovery process and the dependence on the ambient atmosphere.The correction techniques for dose and for depth profile were developed with data fitting.
The probability distribution of the Pearson X2 of small samples was investigated in detail,by use of the period analysis of high energy astrophysical observations as an example.It is pointed out that the commonly used formula of X2 distribution leads to underestimating fluctuation probabilities of large Pearson X2 events if one uses that formula as the probability distribution of the Pearson X2.A new formula is presented for more precise calculation if the Pearson X2 probability distribution and compared with extensive Monte Carlo simulation results.
Local characters of finite state multiplicity spectra in high energy 16O-induced nuclear emulsion(Em)and 32S-induced gold nuclei(~197Au)violent central collisions are investigated systematically.Both the dependences of dispersion on mean value
The Poisson-Lie structure of non-linear -model is given in O(n)/O(n-1)symmetry space,and the covariant relation between moving frame and fixed frame is discussed using the method of covariant decomposition.It is clear that the field dependence of the r and s matrices results from the connection of Sn－1 manifold.
Monte-Carlo simulations of the process e+e－→qq→h's according to the unsaturated model were performed.A kind of longitudinal momentum distribution similar to the constant rapidity distribution in momentum sampling and a particular method to deal with decays of hadrons which contain heavy quarks were used.At the end of this paper we compare results of our MC simulations to experiments.
We deal with the quantum cosmology of the 4+2D dimensional Einstein-Maxwell theory,and calculate minisuperspace wave functions by using the Hartle-Hawking proposal.we find that there exists a class of wave functions that correspond to an observed universe in the classical limit when D≤2.
By virtue of the algebra of the q-deformed fermion oscillators, the q-deformed charged fermion coherent states and SU(3) charged,hypercharged fermion coherent states are discussed.The explicit forms of the two kinds of coherent states mentioned above are obtained by making use of the completeness of base vectors in theq-fermion Fock space.By comparing the q-deformed results with the ordinary results,it is found that the q-deformed charged fermion coherent states and SU(3)charged, hypercharged fermion coherent states are automatically reduced to the ordinary charged fermion coherent states and SU(3)charged,hypercharged fermion coherent states if the deformed parameter q→1.
By using the Fresummation of the hard thermal loops in the tadpole diagrams,the effective potential of orderλ3/2,g3,g'3)is consistently calculated in the standard model with neutral current at high temperature and the difficulties in the naive calculation are overcome.It is proved that the electroweak transition is of the firstorder and the critical temperature is given.
Starting from shell model configurations and effective nucleon-nucleon interactions,we proposed a microscopic approach to study the properties of high-spin states in even-even nuclei in terms of the generalized boson expansion theory.
The low-lying collective energy spectra of cadmium even isotopes are calculated exactly by means of microscopic IBM-2 approach which is based on the Dyson boson expansion and the modified Jancovici-Schiff substitution. The exciting properties of valence proton hole are-analyzed.The results show that the mixed-symmetry states and full-symmetry states of cadmium even isotopes are well described by IBM-2.
The position of saddle point and potential energy surface near the saddle point are studied for a given fissioning system. Multidimensional inertia and viscosity tensors are calculated with both irrotational flow and Werner Wheeler approximation,and the fission rate is calculated with multidimensional Kramers'formula.It is found that the fission rate increases reasonably with the number of dimensions considered and changes only slightly with the assumptions used in kinetic energy calculations.The results of calculations indicate that a suitable three dimensional calculation will be sufficient to yield accurate fission rates.
SYNCH and MAD outputs in calculating lattice with coordinate rotation have been studied in this paper.The result shows that the four dispersion functions(ηx,ηx',ηy,and ηy')given by SYNCH output in this case are wrong.There are large discrepancies between the Twiss Parameters(βx,αx,βy and αy) given by these two programs.One has to be careful in using these programs to calculate or match lattices with coordinate rotations(coupling between two transverse motions) so that to avoid wrong results.
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