1989 Vol. 13, No. S1
Display Method: |
A very typical double core event K5618 was recently observed in Mt. Kanbala emulsion chamber, with the following characters:the zenith angle θ=27°, the total visible energy ΣEγ=547 TeV, and E1=428 TeV, E2=119 TeV respectively for the two cores with a distance R12=25.56 cm between them. It is expected that such an event might give some indications of the signal of the production of extraordinarily large transverse momentum particles in super high energy hadronic interactions.
A superhigh energy gamma-ray family event with the showers distributed in the form of two concentric rings has been found in the ML Kanbala emulsion chamber experiment. The radii of the two rings are 4 mm and 10 mm respectively. This event exhibits some features clearly deviated from those of ordinary big family events. In this paper, some characteristic features of the rings are analyzed and a short discussion is made.
Having considered the similarity between the classical evolution equation and the Schrodinger equation, in this paper we show that a geometric phase factor with topological property,which we call the classical Berry's phase factor, appears properly in the solutions of the classical evolution equations with slowly-changing parameters. The general solutions of the approximate equations in any order in the non-degenerate case are given when the adiabatic condition is violated. As an example, an electrically charged particle moves in an adiabatically varying magnetic field is studied in detail, and a classical model for the Berry's phase factor is obtained explicitly. The phase factor can be explained in geometry as a holonomy of the hermitian linear fiber bundle on a unit sphere S2 of the parameter space.
In the normal fuzzy lattice scheme, the periodicity breaking in the momentum space, thus the avoidance of the unnecessary fermion modes are shown via a self-consistent Fourier transformation. Moreover, the Feynman rule in the weak coupling limit is discussed, the axial vector current anomaly in one-loop perturbation is calculated, and a regular Adler-Bell-Jackiw chiral anomaly is obtained.
A variational calculation is made on the glueball mass in 2 + 1 dimensional SU(2) lattice gauge theory by using a Hamiltonian which possesses exact ground state and correct continuum limit In the range of 1.3 ≤ 1/g2 ≤ 7, a good scaling behavior am=2.28 g2 is obtained, which is in agreement with the weak-coupling perturbation theory and the results obtained by another Hamiltonian which does not possess correct continuum limit.
In this paper the photon angular distributions for the moments of process e+e-→J/ψ→γB(Jη),B(Jη)→P1P2 are derived. It provides a new way to determine the spin of ξ(2230).
The β function behavior of the SU(2)×SU(2) chiral model on a two-dimensional random triangle lattice has been studied with the Monte Carlo renormalization group method. Its behavior is analogous to that of the 4-dimensional SU(2) gauge theory. However, it is smoother from the strong to the weak coupling region. There is no nonperturbative peak structure. The asymptotic scaling starts from β=1,6.
The discussion on kaon condensation at zero temperature given by Brown et al.9 is generalized to that at finite temperature. It shows that the critical nuclear density is little influenced by temperature. A new phase may be formed in heavy ion reaction.
This paper describes the behaviors of the phase transition resulting from the microcanonical Metropolis sampling, with both liquid and gas phases, for the disassembly of hot, dilute and finite nuclei. It concludes that these behaviors are controlled by the competition between the Coulomb force and the flnite size effect.
The Lorentz invariant relativistic optical potential has been discussed at energies below 300 MeV. The Dirac equation with scalar and vector potentials is exactly solved by the partial wave method. The calculated results of proton-40Ca in the energy region 300-65 MeV are presented and compared with the experimental data of the differential cross section dσ/dΩ analyzing power Ay(θ) and spin rotation function Q(θ). It can be shown that the improved relativistic optical potential fits data well.
By using the Hartree-Fork single-particle energies and the wave functions calculated with the density-dependent Skyrme interaction, we re-analyze the contribution of the energy-momentum distribution of nucleons in nuclei to the EMC effect and find that, with those correct single-particle energies and relativistic normalized wave functions, one cannot well explain the EMC effect by only considering the Fermi motion correction including the effect of nuclear binding.
The isoscalar giant surface resonance and giant dipole resonance of highly excited nuclei are discussed. Excitation energies of the giant modes in 208Pb are calculated in a simplified model, using the concept of energy weighted sum rule (EWSR), and the extended Thomas-Fermi approximation at finite temperature is employed to describe the finite temperature equilibrium state. It shows that EWSR and the energy of the resonance depend weakly on the temperature of the system. The weak dependence is analyzed.
A new beta-delayed proton precursor 65Se has probably been produced via the reaction 40Ca(28Si, 3n)65Se and identified from its beta-delayed proton emission. A single proton group at 3.75 + 0.05 MeV with half-life of was observed, corresponding to the 10.8±-3.7+4.1 superallowed beta transition of 65Se to the isospin analog state in 65As (the lowest T=3/2 state in 65As) then decaying by proton emission to the ground state of 64Ge. Because of poor statistics further experimental effort is required to confirm this discovery.
The gamma-ray spectra from niobium under 14.9 MeV neutron bombardments were measured by means of a pulsed T(d,n)4He neutron source, associated particle method, Ge(Li) detector and time-of-flight technique at 7 angles between 30° and 140°. 79 gammalines were determined by a high resolution gamma-spectrum analysis program. The reaction types and the transition levels of 62 lines were preliminarily assigned. Of the 79 gamma-lines, 40 lines were first found in the reactions induced by neutrons. The differential cross sections of every gamma-line at 7 angles were determined. Our study shows that the associated gamma-ray emissions from this reaction are basically isotropic.
By considering the multi-emission effect and the coupling between different chains in the exciton model, the multiplicities in the preequilibrium emission process have been calculated and compared with experimental data.
- A SCOAP3 participating journal - free Open Access publication for qualifying articles
- Average 24 days to first decision
- Fast-track publication for selected articles
- Subscriptions at over 3000 institutions worldwide
- Free English editing on all accepted articles
- The 2023 Chinese New Year-Office closure
- 2022 National holiday- office closure
- The 2022 summer holiday-Office closure
- Impact factor of Chinese Physics C is 2.944 in 2021
- The 2022 Labor Day Holiday-Office closure