1995 Vol. 19, No. 6
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The formation cross sections of target residues have been measured from the interaction of iron with 135MeV/u 12C ions.With the help of assumption of Gaussian charge distribution,the mass yield distribution was obtained.We found that the yield in mass region of A＜30 were notably increased and the products got away to neutron-excessive.The experimental results were compared with calculations based on the statistical fusion fragmentation model and on the sequential binary decay model,respectively. It seems to indicate that the multifragmentation decay mode was the dominant reaction mechanism responsible for production of the fragments with mass number A＜30 in the produce process of target residues under the condition of the higher incident projectile energy.
The principle of Zero-Crossing Timing Method(ZCTM) and the applications of ZCTM to heavy ion nuclear reaction experiments are presented.ORTEC 448 Research Pulser with the Charge Terminator attached was employed in the simulating test measurement of ZCTM.The Laplace transform theory was introduced to account for the simulating experimental data by means of analysing the electronics network of ZCTM.Good agreement was obtained on calculation and simulation
With mountain emulsion chamber data obtained from Mt.Kanbala,the relation between family flux and energy spectrum of showers in the family is investigated.Monte-Carlo generator can reproduce main phenomena of families,and indicates no global change appearing in the hadronic interaction in fragmentation region in the energy region from 1014 to 1015eV.
By studying the Born-Oppenheimer equation for a neutral spin-1／2 particle moving in a spherically symmetrical magnetic field,the non-Abelian Berry's connection in the internal space is found.In the adiabatic approximation,it displays the role of Wu-Yang's monopole.The dynamics for the configurational space is studied by using the concept of section in fibre bundle.Though the angular momentum and energy are quantized,their values are moved.The origination of this phenomenon is geometrical.
The independent source model for hadron-nucleus collisions is generalized to include nucleus-nucleus collisions.A simple analytical formula for transverse energy distributions is derived which is then compared with the experimental data obtained by NA35 Collaboration at CERN.The features of the experimental results are shown to be the natural consequences of the generalized model.
An SO(17) unified model defined in ten dimensions is presented.The model is dimensionally reduced over the coset space SU(3)/U(1)×U(1)×Z2,giving in four dimensions the standard model with three generations of light fermions.
The phase structure of Z4 lattice gauge theory coupled to the Higgs field is studied by using real space renormalization group analysis.The phase diagram showes that the Higgs region is smoothly connected with the confined region.
The renormalization group equation is derived under the scheme of MigdalKadanoff renormalization group transformations.This equation is applied to U(1)lattice group theory.The numerical results for stong and weak coupling regions,including the critical coupling point and the termediate coupling region are presented,which are consistent with the exact results obtained from the strong and weakcoupling expansions and the recent Monte Carlo simulations.
The contributions of Pseudo-Goldstone Bosons in one generation technicolor model to the rare decays t→cV(V= Z,γ,g) are calculated.We find that these new contributions can enhance the SM branching fractions by as much as 3—4 orders of magnitude.The branching fractions can reach to:B(t→ cg)～10－6,B(t→cZ)～10－7,B(t→cγ)～10－8 for the favorable values of the parameters.
The explicit expressions for in-medium NN→N△ cross section are derived within the relativistic Boltzmann-Uehling-Uhlenbeck approach,which are given simultalleously with the other integrants of transport model such as the mean field, NN elastic scattering cross section as well as the transport equation itself based on the effective Lagrangian.Our results can reproduce the experimental data of free inelastic cross section nicely.The in-medium inelastic cross section is calculated up to twice nuclear matter density and is in agreement with the Dirac-Brueckner calculations.
The results of the effective boson numbers in IBM-2 for A≥70 even-even nuclei are reviwed,and the systemapics of the v.s.in rare earch and actinide regions is presented.Here some properties of systematics are discussed and simple explanation is given.Furthermore,by the use of effective boson numbers,the properties of summed B(M1) strengths for even-even nuclei in the actinide region are predicted.
The mechanism of the variance of moment of inertia for well deformed nuclei in the Fermi Dynamical Symmetry Model is discussed.It is shown that without the crossing between I1 band and ground band,the heritage mixture itself also can cause the variance of nuclear moment of inertia.Nevertheless,the form of interaction is important,and the experimental data can be well reproduced by introducing three-body heritage mixing interaction.
Based on the three-body model with Yukawa interactions,the halo nuclei 11Li,14Be and 17B are further studied by the variation calculation.An analytical expression for the density distribution of the halo neutron is given.The theoretical resultsagree with the recent experimental data.
The proportional longitudinal damping system and the constant voltage longitudinal damping system are studied.Formulas determining the parameters of damping system are given.
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