1999 Vol. 23, No. 11
Display Method: |
Analysing the changes of cosmic ray counting rates obtained by the Hial-Rou EAS array in June of 1991, we find a very high energy GLE event after the X solar flare of 15 June 1991. The event started at 1100 UT of the day and lasted about 25 minutes. The counting rate in the 25 minutes for the event exceeds the monthly mean value with about 4σ.
230Pa was produced with the reaction 232TH (p, 3n)230Pa in the irradiation powder targets of ThO2 with 35 MeV Proton beam. Sources of 230Pa -230U were prepared by radiochemical method. Using solid-state track registration detectors, two events of 230U decay with heavy cluster emission have been observed. The preliminary branching ratio to decay comes out to be B=λNe/λα=(1.3±1.8)×10－14.
Unreported heavy neutron-rich nuclide 238Th has been produced via a multinucleon transfer reaction by 60MeVIu 180 ions bombardment of natural uranium.Thorium was radiochemically separated from the mixture of uranium and reaction products. 238Pa as a daughter nucleus of 238Th has been identified according to the growth and decay of 238Pa γ rays which has been observed. The half-life of 238Th was determined to be (9.4 + 2.0) min. At the same time, a new γ ray of (89.0 + 0.3) keV with T1/2= (8.9 + 1.5)min was found in the γ spectrum gated with the Kα1, X ray of Pa and assigned to 238Th decay based on the measurements of its transition energy and the half-life.
An upgrade has been Performed on the barrel shower counter at Beijing spectrometer to improve the Performance of this detector. For Bhabha events, the energy resolution is better than 21% √<span style="border-top: 1px solid; padding-top: 0px;">E</span>(E in GeV) and the spatial resolution along z axis is smaller than 3cm.
Assuming the gauge interactions and gravitation to be trifled in the chiral extension of the standard model, our calculations prove that the generation number of quarks and leptons surely is 3. It is also given that the energy scale of unification is 4.4×1018GeV and the mass scale of leptonic quarks is 1010GeV.
We consider a gauge model based on SU(3)L×U(1)X symmetry. In the model each lepton family contains a new neutral fermion (N-Particle). We calculate the lifetime of the N-particle and estimate the value of its mass. We show that the N-particle can act as dark matter particle.
We calculate the one-loop Z0-penguin contributions to the rare K-decays,K+→π+νν,KL→π0νν and KL→μ+μ－, from the unit-charged pesudo-Goldstone bosons π1 and π8 in the framework of the Multiscale Walking Technicolor Model. We find that: (a) the π1 and π8 can provide one to three orders enhancements to the branching ratios of the rare K-decays under study; (b) the assumed mass ranges of the unit-charged PGBs in the Multiscale Walking Technicolor Model are excluded by the rare K-decay data. According to this and other relavent studies, one finds that the Multiscale Walking Technicolor Model are conflict with the data and therefore excluded.
This article solved energy eigenvalues and eigenfunction of Ring-shaped oscillator by using supersymmetry and shape invariance method. The present energy spectrum formulas are consistent with the exact solutions obtained with the Feynman path integral method
First order correction of thermodynamic potential of QCD at finite temperature are calculated by real-time formulation of Green fuction. The pressure correction of quark-gluon Plasma and the critical temperature correction of deconfinement of hadron are discussed.
On the high energy collisions dynamics distribution of multiparticle production in phace space exist influence unflat distribution. In this paper it is studied carefully for this influence. We have introduce the correction factors, obtained criterion of fitting correction curve and given the method of calculating correction factors.
The effect of the choice of the background on the pion source parameters in two-Pion interferometry analyses in relativistic heavy-ion collisions is studied with the two-Pion interferometry at small relative momentum. The analytic relations between the pion source parameters from two-Pion interferometry analyses with different backgrounds are obtained, and comparison is made with the experimental measurements of the cental relativistic heavy-ion collisions of 1.8 A GeV Ar+Pb.
Using axially-symmetric and triaxial superdeformed models [660 1/2] band in 165Lu is investigated. The observed transition energies can be reproduced quite well in both models. However, the signature staggering index, triaxiality factor and the ratio of dynamical quadrupole moment Q(1) to Q(2) in axially-symmetric superdeformed model are obviously different from those in triaxial superdeformed model, which may be used to identify the deviation of nuclear shape from axial symmetry. Thus, the energy spectra are not decisive to draw the nuclear shape. Emphasis must be Placed on the properties of electromagnetic transitions.
The temporal variation characteristics of nonstationary wave functions are investigated, which enables us to carry out the study of quantum chaotic dynamics with the same starting point as in corresponding classical case, especially to realize the sensitivity of the quantum state with respect to the initial condition. Here the coherent states under the dynamical symmetry of asymmetrical two dimensional harmonic oscillator, in which the minimum uncertainty Principle is satisfied, are usedas an initial state. The formalism of the temporal variation of the expectation values and the uncertainty measurements of canonical variables of the quantum state under the broken symmetry by the additional octupole deformed potential is fulfilled.
As an extension of radioactive ion beam physics, the research on isospin dependent properties of hot nuclei has increasingly attracted considerable interest. The isospin effect on the decay of hot nuclei in reactions 35MeV/u 40Ar+112Sn/124Sn has been investigared. It is concluded that due to Coulomb repulsion and instability, proton-rich hot nuclei probably emit prides such as a with high energy to increase their neutron-proton ratio. Moreover, the decay chain for those particles is seemingly long and the emission Probability is high. Thus, the conventional observations, for instance, the ‘slope temperature’ extracted from energy spectrum, may very appreciably with the measured particles.
The conventional way for the bosonnization of fermions has been based on the Jordon and Wigner scheme. In this paper, we show that this scheme is not correct for k=k′. Therefore the bosonnization of fermions cannot be complete.
A compact 2.45GHz electron cyclotron resonance ion source (ECRIS) for high beam current of single charge state has been nuilt at Institute of Modern Physics. A mixed ion (H1+H2+H3) beam current of 90mA is delivered from a single aperture of φ6mm with rf power 600W at extraction voltage 22kV. This paper introduces the source structure, the magnetic configuration, the test results and the relation between the magnetic configuration and total beam current. In addition, the magnetic configuration is also compared with that of the other 2.45GHz ECR ion scarces built in different laboratories. Finally, some conclusions are presented.
- 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 2019 National Day closure
- Editor Recruitment
- CPC authorship won the âIOP Publishing awards top cited Chinese authorsâ
- The 2019 summer holiday-Office closure
- 2018 Impact Factor 5.861