1997 Vol. 21, No. S1
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In recent years, some short-term enhancements of cosmic ray particles during large solar flares (GLE) were recorded by neutron monitors at sea level and underground muon detectors at different depths. The energy regions concerned have reached to several hundred GeV, even to a few TeV. It is discussed in this paper that the flux enhancement in the TeV region may be the result of re-accelerations of the galactic cosmic rays during large solar flares. Because of the steepness of the energy spectrum of cosmic rays, the re-acceleration of a small part of cosmic ray particles in the GeV region may induce the obvious enhancements of cosmic ray flux in the TeV region.
The emission of light particles in the 10.6 MeV/u 84Kr + 27Al collision in coincidence with fragments is studied. Emphasis is laid on characters of the anisotropic coefficient of the second order based on the fitting particle azimuthal distribution and particle-particle azimuthal correlation via Fourier expansion up to the second order. The derived results prove that particle emission is statistically independent with the same azimuthal distribution. It is found that the anisotropic coefficient of the second order depends weakly on fragment mass and increases with increasing emitted particle mass.
Excitation function fluctuation for projectile-like fragments from 19F + 51V dissipative reaction within the energies of 102.25-109.25MeV are reported in this paper. The statistical method is applied to the analysis of energy coherence in the cross-section fluctuations and the strong cross-correlation between exit channels is obtained. The dependencies of energy, and coherences on charge number and on mass number are presented. The relation between angular velocity damping and the rotational energy dissipation for the dinuclear system is discussed.
High-spin states in 170Ta have been studied via 159Tb (16O, 5nγ) 170Ta reaction at 105 MeV beam energy. Three rotational bands were observed among which one nondistorted band and an unfavored △I=2 E2 sequence in a semidecoupled are newly found by this work. The possible quasiparticle configurations of these bands are also discussed in this paper.
High-spin states of 146Sm have been experimentally studied by using a 13C (95 MeV) beam bombarding a natural thick Ba target; 17 new γ-rays and 11 new levels were found and assigned to the level scheme of 146Sm which was extended up to 10.3 MeV excitation energy. Level structure still shows the characteristics of particle configurations. No long-lived high-spin isomer was found up to such high-excitation regions.
A new group of protons at laboratory energy of 4.07±0.05 MeV with half-life of 32±10 ms was discovered via observing the decay proton spectrum produced in the 32S + Ca reaction. By reaction channel analysis and comparing with theoretical prediction, this new proton radioactivity was assigned to the β-delayed proton decay of 69Kr produced in the 40Ca (32S, 3n) reaction, corresponding to decay of the T=3/2 isobaric analog state in to the ground state of 69Se. Combining this measurement with the Coulomb displacement energy calculation yields a mass excess for 69Kr of -32.15±0.30 MeV. The partial decay scheme of 69Kr was proposed.
The coupling problem of the three different intermediate processes (e.g., J/ψ→ωf2 (1270)，f2→π+π- and J/ψ→b1±(1235) π∓，b1±→ωπ±) included in the hadronic decay process J/ψ→ωπ+π- is discussed. The consideration of the coupling effect is very important for measuring the parameters of the resonances f2 and b1± and the heiicity amplitude ratios of these reactions precisely.
This comment points that the proof of the so-called "irreducibility postulation" is incorrect. The mistake lies in the fact that the symmetrization operator therein has no physical correspondence, and as a consequence, it provides nothing new or interesting in the concept of physics.
The, "cone algorithm" for jet identification is studied in some detail. Two schemes are proposed to identify jets using the momenta of final state particles. Making use of the hadron-hadron collision data sample produced by LUND-PYTHIA Monte Carlo generator, the two schemes are tested and compared with each other. An effective scheme to identify jets is obtained.
The isospin-dependent symmetry energy, Coulomb energy, and N-N cross sections are considered in the quantum molecular dynamics model. The influence of isospin effects on the emission of nucleons is discussed in the head-on collisions of the system 40Ar + 40Ar at the incident energy of 25 MeV/u. It is observed that the ratio of neutron to proton of pre-equilibrium emission is higher than that of the reaction system. It is found that the symmetry energy enhances the emission of neutron but reduces the emission of proton and that the isospin-dependent N-N cross sections favor the emission of both proton and neutron, but they seem to be more beneficial to the emission of protons.
In consideration of the lowest-order nonperturbative effect due to the quark condensate <qq> and the gluon condensate <GG> on the quark propagator, we calculate the QCD nonperturbative quark propagator under the chain approximation. Using the obtained nonperturbative quark propagator, we analyze the nonperturbative effect in the nucleon structure function and show the nontrivial Q2-dependence in the nucleon structure function.
The intrinsic structure of identical bands is demonstrated by using the particle-number-conserving (PNC) treatment. The occurrence of almost identical moments of inertia is the result of competition among the shell effect (including shape variation), the pairing (anti-alignment) effect, and the blocking (antipairing) effect. The observed moments of inertia of identical multi-quasiparticle bands are reproduced quite well by the PNC calculation without free parameters.
This paper reports on a new design of single-cell superconducting cavities. It consists of two half-end cells of the 9-cell Beijing TESLA shape accelerating cavity. The ratio of the maximal surface electric field to accelerating gradient, Ep/Eacc, of the π mode of the 9-cell cavity was reduced to 2.024. The cell-to-cell coupling k is as high as 1.95%. The Ep/Eacc in the single-cell cavities was reduced to 1.8. The monopole, dipole, and quadrupole high-order modes (HOMs) were calculated using URMEL-T with the resistance-band model. In addition, the concept of the structure parameters of the niobium cavity introduced the condition of calculation reliability with the codes; the calculation reliabilities of URMEL and URMEL-T were also discussed.
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