光生相对论的（μ+μ-）,（e+e-）仲原子

本文应用复合场论微扰展开式和相对论的 B-S 近似波函数,计算了类似于 Primakoff 效应的光生相对论的（e⁺e^-）,（μ⁺μ^-）仲原子的过程.结果与通常点模型的计算结果不同,这里多得出了一个新的形状因子.这表明在通常的Primakoff 效应中也将存在类似的修正.     

关于（e+e-）,（μ+μ-）原子在库仑场的裂解

本文应用了复合粒子场论的微扰展开理论和自旋为（1/2-1/2）的库仑相互作用原子的Bethe-Salpeter协变波函数的近似解,计算了（e⁺e^-）（μ⁺μ^-）原子的高速飞行下裂解截面及能谱。结果表明（e⁺e^-）原子的裂解截面比前人的计算约小20％。此外,计算还表明（e⁺e^-）及（μ⁺μ^-）原子的单态和三重态裂解截面对任意主量子数n,和极端相对论近似下将精确相等,而前人的计算中只是n=2时才有这一结果,而对n=1时,两者相差约有25％。看来很可能是计算中的错误所致。     

Event generators for η/η' rare decays into π+π-l+l- and e+e-μ+μ-

Study of the rare and forbidden decays of η/η' offers a sensitive probe to test fundamental symmetries of quantum chromodynamics and search for new physics beyond the Standard Model. To study the rare decays of η/η' to π⁺π^-e⁺e^-, π⁺π^-μ⁺μ^- and e⁺e^-μ⁺μ^- at the BESⅢ detector, we developed several event generators based on the vector meson dominant model with finite-width corrections and the pseudoscalar mesons mixing theory. The various distributions from event generators are in good agreement with the theoretical predictions, which indicates that the event generators work very well after implemention in the BESⅢ Monte Carlo simulation package. In the BESⅢ physics analysis, the performance of the event generators will be improved in accordance with the distributions of different variables of η/η' from data and the improvement on the theoretical calculations.     

Searching for new physics in D0→μ+μ-, e+e-,μ±e干 at BES and/or the super charm-tau factory

In contrast with B⁰-B⁰, B_s-B_s mixing where the standard model (SM) contributions overwhelm that of the new physics beyond standard model (BSM), a measured relatively large D⁰-D⁰ mixing where the SM contribution is negligible, definitely implies the existence of the new physics BSM. It is natural to consider that the rare decays of D meson might be more sensitive to new physics, and the decay mode D⁰→μ⁺μ^- could be an ideal area to search for new physics because it is a flavor changing process. In this work we look for a trace of the new physics BSM in the leptonic decays of D⁰. Concretely we discuss the contributions of unparticle or an extra gauge boson Z' while imposing the constraints set by fitting the D⁰- D⁰ mixing data. We find that the long-distance SM effects for D⁰→l1 still exceed those contributions of the BSM under consideration, but for a double-flavor changing process such as D⁰→μ^±e⁺, the new physics contribution would be significant.     

DISCUSSION ON THE RELATIONSHIP BETWEEN THE FREQUENCIES OF INJECTOR LINAC AND e+e－ STORAGE RING

The question of the relationship between the frequencies of injector linac and storage ring is analysed, especially when sub-harmonic buncher is used. In that case, it seems to be necessary to keep the ratio of two frequencies of the linac and storage ring to be an integer. This question is discussed in detail in this paper from several points of view. As a result of the discussion, two suggestions to avoid the restriction on the frequency relationship are presented.     

THE DOUBLE SPECTRAL FUNCTIONS OF PHOTON-NUCLEON SCATTERING AND INELASTIC CROSS-SECTIONS OF γ+p→p+π++π-

Using elastic unitary condition of t channel, the double spectral function of photon-nucleon scattering and absorbtive parts of scattering amplitude (s channel) are given. Using date of low energy πN(3,3) resonance ρ resonance, the photo-production cross-sections of γ+q+q+π⁺+π- are calculated. The results are compared with the recent experimental data.     

ELECTROWEAK INTERFERENCE EFFECTS IN THE HIGH ENERGY e++e－→e++e－+ HADRONS PROCESSES

In this paper we examine the electroweak interference effects related to the polarized photon structure functions making use of the results of the ref.[2]. The effects provide the probability of a further test of the G-W-S model and may lead to a deep understanding to the photon structure functions.     

Analytic Approximation for Process e++e－→τ++τ－ Cross Section Near Threshold

In the structure function approach,we calculate the threshold behaviours for e⁺+e^－→τ⁺+τ^－,which including QED radiative corrections from initial correction,vacuum polarization effect,Coulomb effect and final state correction.This theoretical prediction for threshold behaviours of τ-pair production is useful for BES new measurement of lepton τ mass.     

A Study of the Processes of e+e－→e+e－,μ+μ－ at Large Angle and Measured Luminosities

Using the BES data collected at √S=4.03GeV.the QED processes of e⁺e^－→e⁺e^－,μ⁺μ^－ have been studied. Our measurements agree with the QED prediction,and luminosities obtained from these two final states are compatible at a level of 4%.The total integrated luminosity of 23.1pb^－1 was given for all data collected at this energy region from the calculation.     

高能e++e－→e++e－+强子过程中的电弱干涉效应

在这篇文章中, 我们用[2]中的结果讨论了与极化光子结构函数相关的电弱干涉效应, 这个效应提供了对G-W-S(格拉肖-温伯格-萨拉姆)模型作进一步检验的可能并且导致对光子结构函数的更深入的了解.     

ON THE “DIRECT CHANNEL DIAGRAM” OF THE PRODUCTION OF THE （π+ π-）s S-STATE ATOMS

In this paper we work out the relativistic covariant B-S wave function for the（π⁺ π^-）_s atoms.Some properties of the“direct channel diagram”of the produc-tion the （π⁺ π^-）_s atoms are discussed by calculating the cross-section of the process π⁺ +n→p+（π⁺ π^-）_s with the help of the relativistic covariant wave function and assuming the lowest termin the perturbation expansion series of the quantized composite field theory——the“direct channel diagram”is dominant.Besides this calcuation perhaps presentsa rough estimate for the interesting process μ⁺ +n→（μ⁺ π^-）+p.     

Determination of J/φ Event Number via J/φ→μ+μ- and J/φ→ e+e- at BESIII

The decays of J/φ→μ⁺μ^- and J/φ→ e⁺e^- are studied by Monte-Carlo simulation, based on the Beijing Spectrometer (BES)Ⅲ offline software system. The methods of determination of the J/φ event number via J/φ→μ⁺μ^- and J/φ→ e⁺e^- are presented, respectively. These methods can be used to determine the J/φevent number for the coming BESⅢ J/φ data sample.     

Analysis of Bs→φμ+μ- decay within supersymmetry

Motivated by the rst measurement on B(B_s→φμ⁺μ^-) by the CDF Collaboration, we study the supersymmetric e ects in semi-leptonic B_s→φμ⁺μ^- decay. In our evaluations, we analyze the dependences of the dimuon invariant mass spectrum and the forward-backward asymmetry on relevant supersymmetric couplings in the MSSM with and without R-parity. The analyses show that the new experimental upper limits of B(B_s→φμ⁺μ^-)from the LHCb Collaboration could further improve the bounds on sneutrino exchange couplings and (δ_LL^u)₂₃ as well as (δ_LL,RR^u)₂₃ mass insertion couplings. In addition, within the allowed ranges of relevant couplings under the constraints from B(B_s→φμ⁺μ^-), B(B→K^(*)μ⁺μ^-) and (B_s→φμ⁺μ^-), the dimuon forward-backward asymmetry and the di erential dimuon forward-backward asymmetry of B_s→φμ⁺μ^-are highly sensitive to the squark exchange contribution and the (δ_LL^u)₂₃ mass insertion contribution. The results obtained in this work will be very useful in searching for supersymmetric signals at the LHC.     

THE FRAGMENTATION OF GLUON OF GLUON IN e+e－ ANNIHILATION

In this paper,we suggest that the gluon is hadronized by first splitting into a quark-anti-quark pair.The final hadrons are produced by the color interactions among the quarks and antiquarke.By this assumption,the calculated average charged particle multiplicities in e⁺e^－→3jet events,and the ratio of multiplicities between gluon and quark jet,and the rates of baryons in e⁺e^－ three gluons events all agree well with experiments.The angle distribution of final particles can be explained.     

ON THE MESONIC MOLECULES (αp,μ－) AND (αp,2μ－)

ACQM is applied to study the μ^－-mesenic molecules (αp,μ^－) and (αp,2μ^－).It is found that the ground state X²Σ⁺ of (αp,2μ^－) is the repulsive one and the ground state X¹Σ⁺ of (αp,2μ^－) is a bound state with the equilibrium proton-proton separation R_e=0.0078bohr and the minimum energy E=－551.78a.u..     

Analysis of Bs→φμ+μ- decay within supersymmetry

Motivated by the rst measurement on B(B_s→φμ⁺μ^-) by the CDF Collaboration, we study the supersymmetric e ects in semi-leptonic B_s→φμ⁺μ^- decay. In our evaluations, we analyze the dependences of the dimuon invariant mass spectrum and the forward-backward asymmetry on relevant supersymmetric couplings in the MSSM with and without R-parity. The analyses show that the new experimental upper limits of B(B_s→φμ⁺μ^-)from the LHCb Collaboration could further improve the bounds on sneutrino exchange couplings and (δ_LL^u)₂₃ as well as (δ_LL,RR^u)₂₃ mass insertion couplings. In addition, within the allowed ranges of relevant couplings under the constraints from B(B_s→φμ⁺μ^-), B(B→K^(*)μ⁺μ^-) and (B_s→φμ⁺μ^-), the dimuon forward-backward asymmetry and the di erential dimuon forward-backward asymmetry of B_s→φμ⁺μ^-are highly sensitive to the squark exchange contribution and the (δ_LL^u)₂₃ mass insertion contribution. The results obtained in this work will be very useful in searching for supersymmetric signals at the LHC.     

STUDY OF THE MECHANISM OF 12C（d,d）12C AND 12C（d,p）13C* REACTIONS

A formalism for studying the interference between the direct reaction and the compound resonance processes is presented by the S-matrix theory; The mechanism of ¹²C（d, d） ¹²C, ¹²C（d, p₁） ¹³C* and ¹²C（d, p₂） ¹³C* reactions in the energy range E_d=1.63 MeV to 2.05 MeV is analysed.Te results show that: the interference between these two processes exists; and the quantitative relation between them is given. While the parameters of direct reactions and compound resonance processes, particularly for four resonance states with E_d=1.726, 1.767, 1.792 and 1.86 MeV are determined.     

在e+e-湮灭中轴子（Axion）的产生及其实验建议

我们计算了在e⁺e^-湮灭中轴子的产生截面,建议利用β⁺放射源在e⁺e^-湮灭实验中寻找轴子。我们还进一步讨论了在这种实验中所用探测器的性能要求。     

D介子衰变Γ（D0→K+K-）/Γ（D0→π+π-）

考虑强作用修正对D⁰介子衰变的影响,用Gilman和Wise^[1]的方法,导出ΔC=1的等效哈密顿量,算得Γ（D⁰→K⁺K^-）/Γ（D⁰→π⁺π^-）～1.26,简单讨论了这种计算方法中的一些问题。     

THE COMBINATION RULE OF QUARKS IN e+e－ ANNIHILATION

We show that the near correlation in rapidity is consistent with the requirements of QCD, and completely determines the combination rule of quarks. We give the formulae for calculating yields of mesons, baryons and antibaryons, which are produced by a stochastic accumulation of quarks with similar rapidities. Using it to e⁺e^－ annihilation, the observation of recently unexpected copious production of baryons is explained naturally.