The kinematic properties of two-body decay near τ threshold are studied according to the special capacity of the BEPCⅡ accelerator and the BESⅢ detector. Explicitly presented are the transformations of energy and momentum of hadronic particles between different reference frames, and the corresponding distributions. A brand new method is proposed to obtain the energy spread of the accelerator by fitting the energy distribution of hadron from τ semi-leptonic decays.

We calculate the branching ratio of B→J/ψ π⁰ with a mixed formalism that combines the QCD-improved factorization and the perturbative QCD approaches. The result is consistent with experimental data. The quite small penguin contribution in B→J/ψ π⁰ decay can be calculated with this method. We suggest two methods to extract the weak phase β. One is through the dependence of the mixing induced CP asymmetry S_J/ψπ0 on the weak phase β, the other is from the relation of the total asymmetry A_CP with the weak phase β. Our results show that the deviation ΔS_{J/ψ π0} of the mixing induced CP asymmetry from sin(－2β) is of O(10^－3) and has much less uncertainty. The above O(10^－3) deviation can provide a good reference for identifying new physics.

Recently, the CDF Collaboration has measured the branching fraction and time-integrated direct CP asymmetry of B__s→K^－π⁺ decay. The branching ratio is lower than the previous predictions based on QCD factorization. The experimental results favor a large CP asymmetry in B_s→K^－π⁺ decay while the standard model prediction is very small. We compute the supersymmetry contributions to B_s→K_－π⁺ decay using the mass insertion method, and find that the LR and RL mass insertions could suppress this branching ratio and increase this direct CP asymmetry well in line with the experimental data.

Ground state entanglement and thermal entanglement of a two-qubit Heisenberg XXZ chain in the presence of the different Dzyaloshinski-Moriya interaction and inhomogeneous magnetic field are investigated. By the concept of concurrence, we find that the inhomogeneity of the magnetic field may make entanglement last for a long time and the critical temperature is dependent on J_z and b. The entanglement can be increased by increasing the temperature in some cases. We also find that the x-component parameter D_x has a higher critical temperature and more entanglement for a certain condition than the z-component parameter D_z.

A hybrid star with a pure quark core, a hadron crust and a mixed phase between the two is considered. The relativistic mean field model for hadron matter and the effective mass bag model for quark matter are used to construct the equation of state for hybrid stars. The influences of medium effects that are parameterized by the strong coupling constant have been discussed on the configuration of rotating stars. The strong coupling constant is a prominent factor that influences the properties of rotating hybrid stars.

According to a new electron screening theory, we discuss the beta decay rates of nuclide ⁵⁶Fe, ⁵⁶Co, ⁵⁶Ni, ⁵⁶Mn, ⁵⁶Cr and ⁵⁶V with and without strong electron screening (SES). The results show that SES has only a slight effect on the beta decay rates for ρ/μ_e<10^8 g/cm³. However the beta decay rates would be influenced greatly for ρ/μ_e≥10^8 g/cm³. Due to SES, the maximum values of the C-factor (in %) on beta decay rates of ⁵⁶Fe, ⁵⁶Co, ⁵⁶Ni, ⁵⁶Mn, ⁵⁶Cr and ⁵⁶V is of the order of 95.03%, 35.02%, 98.05%, 80.33%, 98.30% and 98.71% at T₉ =4.0 and 98.83%, 98.89%, 99.65%, 10.32%, 4.10% and 40.21% at T₉=7.0, respectively.

The effect of the mesons σ^* and Φ and the variety of U_Σ^(N) on the transition density of hyperon stars is examined within the framework of relativistic mean field theory for the baryon octet {n, p, Λ, Σ^－, Σ⁰, Σ⁺, Ξ^－ and Ξ⁰} system. It is found that, compared with that without considering the mesons σ^* and Φ, the transition density of hyperon stars decreases, the critical baryon density that hyperons Σ^－, Σ⁰, Σ⁺, Ξ^－ and Ξ⁰ appears to decrease too, but for Λ the effect is not obvious. As U_Σ^(N) goes up, the critical baryon density of Σ⁺, Σ⁰ and Σ^－ increases, that of Ξ⁰ decreases and that of Λ and Ξ^－ is fixed. In addition, it is found that the variety of U_Σ^(N) almost does not influence the transition density.

In this paper, we include the density dependence behavior of the symmetry energy in the improved quark mass density dependent (IQMDD) model. Under the mean field approximation, this model is applied to investigate neutron star matter and neutron stars successfully. Effects of the density dependence of the symmetry energy on neutron
stars are described.

A dynamical statistical model is used to analyze the experimental shape isomer yields data in the reaction d+²⁴⁰Pu at E=20—29 MeV. The possibility of determining the nuclear dissipation is discussed. Comparison of the experimental data with the calculations leads to a value of the reduced dissipation coefficient β=0.45×10²¹ s^－1 for the Am isotopes.

The transverse mass distributions of protons produced in Au-Au collisions at 8 A GeV and Pb-Pb collisions at 158 A GeV are calculated by using the Monte Carlo method in the framework of the multisource ideal gas model. It is found that our calculated results are in agreement with the experimental data in nucleus-nucleus collisions at high energies.

In order to measure the isotopic ratio of actinides, the upgrade of the accelerator mass spectrometry system at the Center for Isotopic Research on Cultural and Environmental heritage at the Second University of Naples, Italy, was performed. The beam emittance of ²³⁸U and the isotopic abundance sensitivity of ²³⁶U were measured on the present beam line. Utilizing a 16-strip silicon detector, the sensitivity of ²³⁶U/²³⁸U≈1×10^－11 was obtained.

The experimental results of studies of four kinds of cathode emitting intense electron beams are demonstrated under multi-pulsed mode based on an experimental setup including two multi-pulse high voltage sources. The tested cathodes include velvet, carbon fibers, carbon nano-tubes (CNTs) and dispenser cathodes. The results indicate that all four are able to emit multi-pulsed beams. For velvet, carbon fiber and CNTs, the electron induced cathode plasma emission may be the main process and this means that there are differences in beam parameters from pulse to pulse. For dispenser cathodes tested in the experiment, although there is a little difference from pulse to pulse for some reason, thermal-electric field emission may be the main process.

BEPCⅡ is a double ring e⁺e^－ collider with high beam currents and luminosity, so the high beam-related backgrounds may disturb the detector. In order to have a good quality of data taking, backgrounds should be kept at a level as low as possible. A series of collimators are designed and installed in both the e⁺ and e^－ rings. Two of the collimators are horizontally movable, each for one ring, about 8 m upstream from the interaction point. Experiments have been done to identify the effectiveness of the movable collimators with different apertures and beam currents. The results show that the movable collimators are very effective and can reduce as much as about 50% of beam-related backgrounds.

A 52 MHz Radio Frequency Quadrupole (RFQ) linear accelerator (linac) is designed to serve as an initial structure for the SSC-Linac system (injector into Separated Sector Cyclotron). The designed injection and output energy are 3.5 keV/u and 143 keV/u, respectively. The beam dynamics in this RFQ have been studied using a three-dimensional Particle-In-Cell (PIC) code BEAMPATH. Simulation results show that this RFQ structure is characterized by stable values of beam transmission efficiency (at least 95%) for both zero-current mode and the space charge dominated regime. The beam accelerated in the RFQ has good quality in both transverse and longitudinal directions, and could easily be accepted by Drift Tube Linac (DTL). The effect of the vane error and that of the space charge on the beam parameters have been studied as well to define the engineering tolerance for RFQ vane machining and alignment.

A proton radiography system is an accelerator-based facility. Especially high-energy proton radiography is an advanced hydrodynamics diagnostic tool, and it is the trend of radiography technology development. In this paper, a 20 GeV accelerator complex scenario, including
a 35 MeV linac, a 1 GeV booster and a 20 GeV main ring, is introduced. The overall physics design of the proton radiography accelerator is described, including the design of each part of the accelerator and the choice of the main parameters.

Superconducting quarter-wave resonators, due to their compactness and their convenient shape for tuning and coupling, are very attractive for low-β beam acceleration. In this paper, two types of cavities with different geometry have been numerically simulated：the first type with larger capacitive load in the beam line and the second type of lollipop-shape for 100 MHz, β=0.06 beams；then the relative electromagnetic parameters and geometric sizes have been compared. It is found that the second type, whose structural design is optimized with the conical stem and shaping drift-tube, can support the better accelerating performance. At the end of the paper, some structural deformation effects on frequency shifts and appropriate solutions have been discussed.

In this paper, a dedicated synchrotron radiation (SR) mode for the BEPCⅡ with an emittance of 85 nm has been designed, including the linear lattice, chromaticity correction and dynamic aperture optimization. The emittance of the new mode is about 60% of the previous mode used for routine operation of the BEPCⅡ. The effect of wigglers on the linear lattice was
compensated and the total dynamic aperture including the wigglers' nonlinear effect was estimated. The preliminary commissioning at the end of 2008 and the formal operation with the new mode confirmed its merits.

The construction of the China Spallation Neutron Source (CSNS) has been initiated at Dongguan, Guangdong, China. In spallation neutron sources the target station monolith is contaminated by a large number of fast neutrons whose energies can be as large as those of the protons of the proton beam directed towards the tungsten target. A detailed radiation transport analysis of the target station monolith is important for the construction of the CSNS. The analysis is performed using the coupled Monte Carlo and multi-dimensional discrete ordinates method. Successful elimination of the primary ray effects via the two-dimensional uncollided flux and first collision source methodology is also illustrated. The dose at the edge of the monolith is calculated. The results demonstrate that the doses received by the hall staff members are below the required standard limit.