1999 Vol. 23, No. 9
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The pseudorapidity distribution for charged prides Produced in pp collisions at 400GeV/c has been measured by using the LEBC films offered by the CERN NA27 collaboration. The fastorial moments up to q=7 have been calculated by star integer method. The analytic results indicate that a non-thermal phase transition and two different regimes of multiparticle production may exist. The multifractal structure of the fluctuation has been observed supporting the random cascade model of particle production.
The track reconstruction of BES barrel shower counter was presented and the shower finding, pattern recognition technique were described. The reconstruction results from experimental data were presented and discussed.
In a certain gauge, we get a new Lax operator for trigonometric Calogero-Moser model. The conesponding r-matrix is shown to be nondynamical . Atthe same time, we find that trigonometric Calogero-Moser model and trigonometric Ruijsenaars -Schneider model are governed by the completely same nondynamical r-matrix.
An analysis is made for the (0s)6 six quark cluster states in the chiral SU(3)quark model. The results show that for some states with higher strange number the chiral SU(3) cloud offers more attraction. and these informations are useful to discussif there exists some narrow width six quark states.
In this paper, the Schrodinger equation with a non-spherical harmonic oscillator potential in three dimensions V（r）=1/2r2+A/2r2 is solved. The exact energy equation and the normalized wave function are obtained. The calculation formulas andrecurrence formulas of matrix elements and mean values for any integer power operator rs are presented.
The quantized Hamiltonian is derived from the general parametral form of the hexadecapole Vibration in the space of parameter, which maybe important to analyze properties of nuclear stature.
We test the Gerasimov-Drell-Hearn (GDH) sum rule numerically by calculating the total photon absorption cross sections σ1/2 and σ3/2 on the nucleon via photon excitation of baryon resonances in the constituent quark model. A total of seventeen, low-lying, non-strange baryon resonances are included in mis calculation.The transverse and longitudinal interference cross section, σ, is found to play an important role in the study of the Q2 variation of the sum rule. The results show that the GDH sum rule is saturated by these resonances at a confidence level of 94%. Inparticular , the P33,(1232) excitation largely saturates the stun rule at Q2=0, and dominates at small Q2. The GDH integers has a strong Q2-dependence below Q2=1.0GeV2 and changes its sign around Q2=0.3GeV2. It becomes weakly Q2-dependence for Q2>1.0GeV2 because of the qinck decline of resonance contributions.
High spin states of 84Rb were populated by the 70Zn (18O,p3n) reaction at 75MeV 18O beams provided by the HI-13 Tandem Accelerator of CIAE. Excitation function, gamma-gamma coincidence and DCO Ratio were measured by using 8 BGO Compton-supton-suppressed HPGe spectrometers and a planar HPGe detector. More than 40excited states and 50 γ rays were identified in the Present work. A new level scheme of 84Rb was established, in which the positive and negative bands are extended to 17+and 17－ respectively . Comparing the odd-odd Rb isotopes and N=47 isotones, the similar structure is observed in their low excited states.
It is discussed the equivalent properties between QMC and QHD models,and then, the in-medium QMC model parameters are determined self-consistently. The results demonstrate that the bag constant and the nucleon radius are greatly influenced by nuclear medium, however, the parameter for the zero-point inchon keeps the same value as in vacuum. The critical curve shows that the QMC model parameters determined in our scheme are valid in low density region (ρ≤1.75ρ0,) todiscuss the finite nuclei and nuclear matter properly.
The projection geometry stature of torsion on 3 dimensional Riemann Cartan manifold have been studied. It shows that the geomeny origin of linkingnumber may correspond to the projection torsion structure via both Chern-Simons theory and Witten's topological field theory. Furthermore, it is also indicated lines by means of a quanhzation method in which the quantum number is detennined by Hopf indices and Brouwer degree that wilson loops may defect lines.
The method to calculate the RF cavity higher-order modes (HOMs) power generated by unequally spaced and populated bunches in the storage rings with single beam and colliding beams is developed and presented in this paper. The corresponding analytical formulas for calculating the HOMs power are derived.
The generalized Crewther relation relates the cross section ratio R=σ(e+e－→hadrons)/σ(e+e－→μ+μ－) in e+e－ annihilation with the Bjorken sum rule or the Gross-Llewellyn Smith sum rule in deep inelastic scattering and provides a fundamental connection for observables in Quantum Chromodynamics (QCD) without scale or scheme ambiguities. The ratio R can be measmed at the upgrated Beijing Electal Positron Collider or the τ-Charm factory with higher precision and thus can be served for a high Precision test of QCD in the standard model.
In the large Nc expansion beyond mean-field approximation, we develop a generals scheme of SU(2) NJL model including current quark mass explicitly. In our scheme, the conshttituent quark's propagator is expanded in pion's external momentum k, and all the Feynman diagrams are naturally expanded to k2 term in a unified way. Our numerical results show that in the mean field appproximations the effect of current quark mass is invisible, however, the effect of current quark mass can be seen explicitly beyond mean-field approximation for reasonable choices of the parameters in NJL model.
The excitation of Higher, Order Modes (HOM) in an accelerator can lead to cumulative beam break up, therefore, these modes have to be suppressed. For the S-Band Linear Collider (SBLC), it has been suggested to cover the disk loaded strucks at the iris with an aPPropriate loss malarial. For the high-power test of the iris coating a resonator consishng of tWo cells of the SBLC is used. This paper describes the high-power test and gives some Preliminary results.
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