Helicity Amplitude Analysis of ηc Decays into Hyperon-Antihyperon Pairst

The helicity amplitudes for the processes of e^＋e^- →J/ψ→γηc→γYY（Y： hyperon） are presented, together with the joint angular distributions for ηc decays into ∧∧,∑^0 ∑^0, and [1]-[1]＋. The sensitivities to measure the hyperon decay parameters in these decays are evaluated based on the helicity amplitudes. The prospects to test the Bell inequality in experiment using the decay of ηc→∧∧ are discussed.     

Uncertainty study of Bd(Bs)→ γν \bar{ν} Decays

B⁰(B_s) → γν\bar{ν} decays are useful to determining the decay constants f_B(f_{B_{s}}) and B(B_s) meson wave function. Using the B meson wave function determined in hadronic B(B_s) decays, we study the uncertainties due to the types of B meson wave functions. We find that the branching ratios are sensitive to the type of wave functions and input parameters, but the energy spectrum is independent. The predicted branching ratios are (0.45-1.04)× 10^-9 and (2.14-3.27)×10^-8 for B⁰ and B_s decay, respectively.     

B → Ds(*) η (') Decays in Perturbative QCD

In this paper, we calculate the branching ratios for B⁺ → D_s⁺η, B⁺ → D_s⁺η ', B⁺ → D_s^*+η, and B⁺ → D_s^*+η ' decays by employing the perturbative QCD (pQCD) factorization approach. Under the two kinds of η-η' mixingschemes, the quark-flavor mixing scheme and the singlet-octet mixingscheme, we find that the calculated branching ratios agree well withthe currently available experimental upper limits. We also consider the so called ``f_{D_s} puzzle', by using two groups of parameters about the D^(*)_s meson decay constants, that are f_{D_s}=241 MeV, f_{D^*_s}=272 MeV and f_{^D_s=}274 MeV, f_{D^*_s}=312 MeV, to calculate the branching ratios for theconsidered decays. We find that the results change 30% by usingthese two different kinds of paramters.     

Analysis of Infrared Divergence in OZI-Forbidden Decays of Orthoquarkonia

It is interesting to investigate the OZI-forbidden decays of orthoquarkoknium, J/ψ→γπ^0（γη,γη′）, J/ψ→π^＋π^-（π^0π^0）. At first glance, there is infrared divergence in the above processes. In this work, to clear the mist we use the factorization method with the light cone wavefunction of the final state light meson. We prove straightforwardly that the infrared divergence can be eliminated completely.     

激发功率、退火温度及Tm3+浓度对Tm3+/Er3+/Yb3+三掺YF3粉末上转换发光性质的影响

用水热法合成了Tm³⁺/Er³⁺/Yb³⁺三掺杂YF₃上转换发光粉末,并对其进行了结构和形貌表征.对上转换发射谱的研究表明,在相对低激发功率下,可以观察到比较明亮的近白色发光,且随着激发功率的增大,上转换发射强度迅速增大并达到饱和状态,继续增大激发功率,出现发光猝灭现象.退火温度对上转换发射强度的影响表明,随着退火温度的升高,Tm³⁺,Er³⁺的所有特征发射峰均相对增强.上转换发射谱随Tm³⁺浓度变化关系表明,在相对低Tm³⁺掺杂浓度下,Tm³⁺-Er³⁺相互作用占优势,Tm³⁺把能量传递给Er³⁺,Er³⁺发射相对增强;在相对高掺杂浓度下,Tm³⁺-Tm³⁺之间交叉弛豫过程占优势,Er³⁺发射相对减弱.从实验结果看出,该粉末的上转换发光非常丰富,从紫外到红外均有发射,是一种潜在的白色上转换发光及三维固体显示材料.     

Study of Radiative Decays Ds1(2536) → Ds(1968)+γ andDs1(2536) → Ds*(2112)+γ in CQM Model

There are some uncertain characteristics of the D_s1(2536), which deserves further discussion. Based on the assumption that the meson is constituted by c\bar{s}, and belongs to T doublet (1⁺,2⁺), radiative decays D_s1(2536)→D_s(1968)+γ and D_s1(2536)→ D_s*(2112)+γ are studied in the CQM model. The large branching ratios of them from our calculations not only indicate the process may be detected in the future experiments, but also can give a deep comprehension of the structure of it.     

{Q\bar{s}}{\bar{Q}(') s} Molecular States in QCD Sum Rules

We systematically investigate the mass spectra of {Q\bar{s}}{bar{Q}^(')s}molecular states in the framework of QCD sum rules. The interpolating currents representing the molecular states are proposed. Technically, contributions of the operators up to dimension six are included in operator product expansion (OPE). The masses for molecular states with various{Q\bar{s}} {\bar{Q}^(')s} configurations are presented. The result 4.36±0.08 GeV for the D^*_s\bar{D}^*_s0 molecular state is consistent withthe mass 4350^+4.6_-5.1 ± 0.7 MeV of the newly observed X(4350), which could support X(4350) interpreted as a D^*_s\bar{D^}*_s0 molecular state.     

NLO Corrections of HTC Π0 and Π+Π- Pair Production at ILC in TC2 Model

As well known, if the Higgs boson were not observed at LHC, the technicolor model would be the most favorable candidate responsible for the symmetry breaking. To overcome some defects in the previous model, some extended versions have been proposed. In the TC2 model typical signature is existence of heavy H_TC and technipion Π. A direct proof of validity of the model is to produce them at accelerator. Thus we study the production rates of e⁺ e^- → H_TCΠ⁰ and e⁺ e^- → Π⁺ Π^- at ILC in the topcolor-assisted technicolor (TC2) model. In fact, there is a flood of models belonging to new physics, which can result in products withcharacteristics similar to H_TC+Π of the TC2 model. Therefore to distinguish this model from others one may need to investigate some details by calculating the cross section to NLO. We indeed find that the NLO corrections are significant, namely the ratio δ ≡ (σ_NLO- σ_LO)/σ_LO in e⁺ e^- → H_TC Π⁰ exceeds 100% within a plausible parameter space.     

Production of Charged Higgs Bosons from Left-Right Twin Higgs Model at TeV Energy e-γ Colliders

The left-right twin Higgs (LRTH) model predicts the existence of three additional Higgs bosons: one neutral Higgs ø⁰ and a pair of charged Higgs bosons ø^±. In this paper, we study two pair production processes of these new particles at the next generation eγ colliders, i.e., e^-γ → e^-ø⁺ø^-, ande^-γ→ ν_Rø^-ø⁰. We find that the production cross section of the process e^-γ →e^-ø⁺ø^- are at the level of several tens fb, the production cross section of the process e^-γ→ν_Rø^-ø⁰ can reach 0.35 fb with the reasonable parameter values. As long as the charged Higgs bosons are not too heavy, we conclude that these processes might be used to test for the left-right twin Higgs model in future high-energy linear collider experiments.     

喷雾热解法制备红色发光粉LiEu(SiO2)1/6W2O8的研究

采用喷雾热解法制备红色荧光粉LiEu(SiO₂)_1/6W₂O₈。研究了反应温度、前驱体溶液浓度、载气流速对实验结果的影响。通过扫描电镜、X射线衍射、激发和发射光谱对所制样品进行了研究,发现样品颗粒呈实心类球形、结晶度好、表面光滑、发光强度较高、粒径平均1.5μm左右且分布较窄。该类荧光粉激发主峰位于396nm,发射主峰位于615nm。LiEu(SiO₂)_1/6W₂O₈发光的色坐标为:x=0.667 9,y=0.3310,与NTSC的红色标准基本一致,该荧光粉色纯度非常高,适用于制造紫光芯片激发的白光LED。用喷雾热解法制备红色荧光粉LiEu(SiO₂)_1/6W₂O₈的研究尚未见报道。     

Quark-Antiquark and Diquark Condensates in Vacuum in Two-Flavor Four-Fermion Interaction Models with Any Color Number Nc

The color number Nc-dependence of the interplay between quark-antiquark condensates （q^-q） and diquark condensates （qq） in vacuum in two-flavor four-fermion interaction models is researched. The results show that the Gs-Hs （the coupling constant of scalar （q^-q）2-scalar （qq）2 channel） phase diagrams will be qualitatively consistent with the case of Nc = 3 as Nc varies in 4D Nambu-Jona-Lasinio model and 219 Gross Neveu （GN） model, However, in 3D GN model, the behavior of the Gs-Hp （the coupling constant of pseudoscalar （qq）^2 channel） phase diagram will obviously depend on No. The known characteristic that a 3D GN model does not have the coexistence phase of the condensates （q^-q） and （qq） is proven to appear only in the case of Nc ≤ 4. In all the models, the regions occupied by the phases containing the diquark condensates （qq） in corresponding phase diagrams will gradually decrease as Nc grows up and finally go to zero if Nc → ∞, i.e. in this limit only the pure （q^-q） phase could exist.     

Tunneling Conductance in dx2-y2+idxy Mixed Wave Superconductor Graphene Junctions

Using the extended Blonder-Tinkham-Klapwijk formalism, we investigate the conductance spectra of normal metal/d_x²-y²+id_xy mixed wave superconductor graphene junctions. It is found that the conductance spectra vary strongly with the orientation of the gap and the amplitude ratio (Δ₁/Δ₀) of two components for d_x²-y²+id_xy mixed wave. The zero bias conductance isnearly 2 and the conductance peak vanishes in doped graphene forα=0 and Δ₁/Δ₀=1. The conductance increases with increasing the amplitude ratio of two components for α=π/4 and Δ₁/Δ₀=1. The ZBCP becomesobservable wide with 1F/Δ₀<100 for α=π/4 and Δ₁/Δ₀=1. This property is different from that in normal metal/d_x²-y² wave superconductor graphenejunctions.     

Complex-Variable Fokker-Planck Equation Solved in Entangled State Representation

We lind that the Fokker-Planck equation in complex variables can be conveniently solved in the context of bipartite entangled state representation and its relationship with SU（2） Lie algebraic generators＇ new realization {（1/4）[（Q1 - Q2）^2 ＋ （P1＋ P2）^2], （1/4）[（Q1 ＋Q2）^2＋ （P1 - P2）^2], and -（i/2）（Q1P2 ＋ Q2P1）}, the quadratic combination of canonical operators.     

Allowable Generalized Quantum Gates

In this paper, we give the most general duality gates, or generalized quantum gates in duality quantum computers. Here we show by explicit construction that a n-bit duality quantum computer with d slits can be simulated perfectly with an ordinary quantum computer with n qubits and one auxiliary qudit. Using this model, we give the most general form of duality gates which is of the form ∑i=0^d-1piUi,and the pi ＇s are complex numbers with module less or equal to 1 and constrained by｜∑iPi｜≤1.     

Spontaneous U（1） Symmetry Breaking in Coupled Bose System

Adding a U(1) symmetry breaking term V^1/2 a(λ₁a₀+λ*₁a^&#8224;₀)+V^1/2(λ₂b₀+λ^*₂b^&#8224;₀) to Bogoliubov's truncated Hamiltonian H_B for a weakly interacting coupled Bose system, by using the mean-field approximation rather than the c-number approximation, we find that, via a Feshbach resonance at zero temperature, the states of the coupled Bose system are generalized SU(1,1) × SU(1,1) coherent states. The Bose-Einsteincondensation occurs in response to the spontaneous U(1) symmetry breaking.     

Searching for Flavor-Changing Neutral-Current Signalsvia e+e-(γγ) → t\bar{c}h0t in Topcolor-Assisted Technicolor Model

In the context of the top-color-assisted technicolor (TC2) model, the flavor-changing neutral-current (FCNC) interaction induced by the top-higgs (h⁰_t) are predicted at tree level. We study the relevant processes of e⁺e^-(γγ)→ t\bar{c}h⁰_t at the International Linear Collider (ILC). It is found that these rare processes production rates can be enhanced significantly in the TC2 model. Especially for the process γγ → t\bar{c}h⁰_t, the total cross section will reach a few fb in the reasonable parameter space. We also calculate the distributions of transverse momenta, pseudo-rapid and invariant mass of the top-higgs. In view of the main decay modes of top-higgs for m_h⁰t<2m_t, we find that there will be several hundreds FCNC events produced at the ILC with annuallyintegral luminosity of 500 fb^-1. Due to the clean background, such FCNC signals can possibly be detected at the ILC.     

Charged Top-Pion Production at Hadron Colliders

We studied the charged top-pion in the topcolor assisted technicolor model (TC2). If the charged top-pions are heavy, m_πt >m_t+m_b, they will decay mainly via the channel π⁺_t → t \bar{b}. We also calculated the production ofcharged top-pion at the Tevatron and LHC. The cross section can reach to 100 fb at the Tevatron and dozens of pb at the LHC depending on the mass of the top-pion.     

Hadron molecules

We discuss a possible interpretation of the open charm mesons D*s0 (2317),D s1 (2460) and the hidden charm mesons X(3872),Y(3940) and Y(4140) as hadron molecules.Using a phenomenological Lagrangian approach we review the strong and radiative decays of the D* s0 (2317) and D s1 (2460) states.The X(3872) is assumed to consist dominantly of molecular hadronic components with an additional small admixture of a charmonium configuration.Determing the radiative (γJ/ψ and γψ(2s)) and strong (J/ψ2π and J/ψ3π) decay modes we show that the present experimental observation is consistent with the molecular structure assumption of the X(3872).Finally,we give evidence for molecular interpretations of the Y(3940) and Y(4140) related to the observed strong decay modes J/ψ+ω or J/ψ+φ,respectively.     

Looking for new gauge bosons in radiative decays of pseudoscalar mesons

We perform the model independent analysis of possibilities of looking for new gauge bosons in radiative decays of π⁰, η, η′ mesons. For this purpose we consider various experimental constraints on properties of light gauge bosons. It is shown that the branching ratios of these decays can be as large as: BR(π⁰→γ+X)?10^?3, BR(η→γ+X)?10^?4, BR(η′→γ+X)?10^?6, what is highly interesting from the experimental point of view.