Determination of J/ψ Leptonic Branching Fraction Via ψ(2S)→π+π－J/ψ

Two processes ψ(2S)→π⁺π^－J/ψ,J/ψ→1⁺1^－ and J/ψ→anything are carefully studied to get the J/ψ leptonic branching fractions with the ψ(2S)data at BES/BEPC.The results are B(J/ψ→e⁺e^－)=(5.90±0.07±0.16)% and B(J/ψ→μ⁺μ^－)=(5.96 ±0.08±0.16)%,and B_e/B_μ is estimated to be 0.990±0.018±0.024.Assuming B_e=B_μ,the leptonic branching fraction of the J/ψ is B(J/ψ→1⁺1^－)=(5.93±0.05 ± 0. 16 )%.This result is used to estimate the QCD scale factor ∧(nf/MS) and the strong coupling constant α_s.     

A STRUCTURE MODEL OF STRATONS AND LEPTONS

A subquark model is proposed. According to this model, stratons and leptons are consisted of rishons T and V, which are multiplets of group SU_H(3)×SU_C(3)×SU_G(2)×SU(2)×U(1). Three generations of both stratons and leptons are obtained naturally. In this model, proton decay modes are μ^－e⁺e⁺ or e^－μ⁺μ⁺.     

Charged Top-Pions Corrections to the Top Quark Production at LC in TC2 Theory

We discuss the contributions of PGBs (technipions and top-pious) to the top quark production in TC2 theory at the high energy e⁺e^－ linear collider (LC) experiments. We find that the corrections to the production cross section σ_tt mathly come from top-pious. The corrections of the charged top-pious are significantly large in most of the parameter space. With reasonable value of the parameters, the correction to σ_tt can reach about 8% which may be detected at LC experiments.     

Measurement of J/ψ→ηcγ at KEDR

We present a study of the inclusive photon spectra from 5.9 million J/ψ decays collected with the KEDR detector at the VEPP-4M e⁺e^－ collider. We measure the branching fraction of radiative decay J/ψ→η_cγ, η_c width and mass. Our preliminary results are: M(η_c)=2979.4±1.5±1.9 MeV/c², Γ(η_c) = 27.8±5.1±3.3 MeV, B(J/ψ→η_cγ)=(2.34±0.15±0.40)%.

     

Radiative Corrections to the Zbb and Zτ+τ－ Vertices in a Realistic One-Family Extended Technicolor Model

In a realistic effective one-family extended technicolor(ETC)model without exact custodial symmetry, we calculate the one-loop corrections to the Zbb and Zτ⁺τ^－ vertices from the sideways and diagonal ETC gauge boson exchange.The results show that both the Z→ bb partial Width Γ_b and branching ratio R_b and the τ polarization asymmetry parameter A_τ are enhanced by the corrections and are in agreement with the present experimental data.     

Electroweak radiative corrections to the e+e− →+− asymmetry

The electromagnetic and purely weak one-loop corrections to e⁺e^? →^+? have been calculated in the SU(2) × U(1) standard model using an on-shell renormalisation scheme with finite Green functions. Thier influence on the forward backward asymmetry A_FB together with soft and hard bremsstrahlung is discussed for PETRA energies. Whereas the electromagnetic corrections to ψ and Z⁰ exchange diminish A_FB, the weak corrections increase A_FB almost compensating the QED correction to Z⁰ exchange. The main weak contribution comes from the Z⁰ self-energy. The other diagrams give only small changes in A_FB.     

The Spin Effect of Antiproton-Nucleus Inelastic Collison

If the antiproton optical potential is inclusive of the spin orbit interaction term,the A(p,p)A* inelastic scattering not only can excited the normal parity states,but also can excited the abnormal parity states.There are also induced the polarization P_f(θ) at the inelastic scattering.In the framework of DWIA,we derived the inelastic scattering cross section (dσ/dΩ)_f,i,and polarization P_f(θ),and calculated the (dσ/dΩ)_f,i, and P_f(θ) for ¹²C(p,p)¹²C* with 2⁺,3^－ and 1⁺ states at antiproton energies of 46.8 and 179.7MeV.They fited experiment data quite well.Due to the abnormal partity states in the inelastic process have been measured,the spin orbit term can not be neglect.     

DECAY PROCESSES IN MASSIVE STRATON MODEL OF MESONS

Using the B-S wave functions of mesons in the massive straton model^[1], we discuss their weak decay, electromagnetic decay, and particularly hadronic decay processes. Not only f_π≈f_K, 1^－→l⁺l^－ rate are successfully explained, the predicted widths for various hadronic decays are also in good agreement with experimental data.     

SOME CONJECTURES ON THE MASS FORMULA OF CHARGED LEPTONS

In this note we propose that the electromagnetic self energy of lepton may beconnected with quantum number n by（ （δm）/m）=（1/（2π））n^-b ,in which b is a constant.Wefnrther propose that the cut-off value of momentum M is connected with gravitationalconstant κ and fine structure constant α by M=（1/√κ）αe^-1-b.So we obtainthe mass formula of charged leptons M=（1/√κ）α exp{-3/4-b-(1/3α)n^-b}.By using the masses of e^- and μ^- and the value of a as in put,we get the calculatedvalues of κ=（6.67231±0.00026）×10^-8cm³g^-1sec^-2and m_r=（1782.306±0.078）MeVwhich agree very well with experimental values κ=（6.6720±0.0041）×10^-8cm³g^-1sec^-2 and m_τ=(1782_-4⁺³)MeV respectively.The mass of the fourth charged leptonpredicted by the formula should be m=（11725.47±0.51）MeV,which can be checkedby experiments in the near future.We also discuss briefly the proposed formula andthe obtained results.     

TESTING GLUON DISTRIBUTION FUNCTION OF HADRONS IN LARGE PT PROCESS WITH DIRECT PHOTON EMISSION

In this paper we disscuse disscuse the physicsical aspect of cross-section differences Δ_AB^cγ=dσ(AB→cγX)-dσ(AB→cγX) and give the simple rules to select the elementary subprocesses which contribute to cross-section differences.
We bind a way to test the gluon distribution functions of hadrons through the measurement of cross-section difference or combination of cross-section differences in the large P_T process with direct photon emission. Moreover we obtain simple relations between each combination of cross-sections and the corresponding gluon distribution functions of proton, neutron, pion and daon:
G_p⁸(x)/(Δ_pp^hγ－Δ_pp^hγ)=G_n⁸(x)/(Δ_pp^hγ)=G_π⁸(x)/(Δ_π+p^hγ+Δ_π－p^hγ=G_K⁸(x)/(Δ_K+p^hγ+Δ_K－p^hγ)which are expected to be test in experiment.     

THE DIFFICULTY OF THE DECAY τ→πντ AND SPIN 3/2 HEAVY LEPTON

We discuss the suppression of the decay of heavy lepton τ into πv_τ,by assuming that τ and/or v_τ carry spin 3/2. For the case of spin 3/2 T and spin 1/2 v_τ, using the weak current ψ_μ^(τ)(a+b_^γ5)Ψ^(v_τ)we find that the πv_τ decay channel relative to the v_τv_ll^-channel is suppressed 12/5 times, while other decay channels are not changed appreciably. △R=σ（e⁺e^-→τ⁺τ^-）/σ（e⁺e^-→μ⁺μ^-） is also discussed.     

Observation of a pp mass threshold enhancement in ψ′→π+π－J/ψ(J/ψ→γpp) decay

The decay channel ψ′→π⁺π^－J/ψ(J/ψ→γpp) is studied using a sample of 1.06×10⁸ ψ′ events collected by the BESIII experiment at BEPCII. A strong enhancement at threshold is observed in the pp invariant mass spectrum. The enhancement can be fitted with an S-wave Breit-Wigner resonance function with a resulting peak mass of M=1861⁺⁶_－13 (stat)⁺⁷_－26 (syst) MeV/c² and a narrow width that is Γ<38 MeV/c² at the 90% confidence level. These results are consistent with published BESII results. These mass and width values do not match with well established mesons.

     

Yields of Charmed and Beautiful Mesons in e+e－ Annihilation at s=10—178GeV 的e+e-

Based on the electroweak unified standard model,the probability P_i for the production of i-quark jet (i=u,d,c and b)in e⁺e^－ annihilation has been studied.The probability P_i is a function of energy s.The calculated component ratios of P_u:P_d:P_s:P_c:P_b are 4:1:1:4:1 for s<30GeV.7:9:9:7:9 for s=m_z=91.16GeV and 1:1:1:1:1 for s=78 and 117GeV,respectively.Using P_c and P_b,we whave calculated the yields of charmed and beautiful mesons in e⁺e^－ annihilation at s=10—178GeV.     

Research of bb Production in the Topcolor Assisted Technicolor Model

In the framework of topcolor assisted technicolor (TC2) model, we calculate the contributions of cross section from the pseudo Goldstone bosons and new gauge bosons to e⁺e^－ →bb. We find that, within reasonable ranges of the parameters, the corrections arising from technipions and new gauge bosons are negligibly small; and the top pions afford dominate contribution, the maxim cross section corrections can reach 43% with the c.m. energy √s=500GeV; whereas in case of √s=1500GeV, the maxim cross section relative corrections is only 3.1%. It might open a window to detect topcolor assisted technicolor model in the experiment of next generation linear collider.     

AN ANALYSIS OF FOUR-ELEMENT MODELS OF LEPTONS AND NON-DIAGONAL NEUTRAL CURRENTS

Due to the possible production of neutral and charge heavy leptons by v_μ, models consisting of four elements per "line", e.g. v_e, e^-, E⁰, E^- v_μ, μ^-, M^0, M^- v_τ, τ^-, T⁰, T^- ……are analysed. Non-diagonal neutral currents cannot be avoided. Nevertheless, a model is proposed within SU_（2）×U_（1） in which the process μ→eγ can still be suppressed by the Bjorken-Lane-Weinberg mechanism; various production cross-sections for heavy leptons are reasonable when compared with experiments. Models corresponding to SU_（3）×U（1） and still higher symmetries are discussed.     

HELICITY FORMALISM OF THE ANGULAR DISTRIBUTION FOR THE J/ψ HADRONIC DECAY PROCESS

In this paper we give the helicity formalism of the angular distribution for processes e⁺e^－→J/ψ→V+X,V→P₁P₂ and e⁺e^－→J/ψ→V+X,X→P₄P₅.It provides the theoretical formula for e⁺e^－ experimental data analysis.     

QCD and QED corrections to the longitudinal polarization asymmetry

The interplay between QED and QCD corrections to the longitudinal polarization asymmetry,A _LR, ine ⁺ e ^?, annihilation is studied. It is found that measurements with hadronic final states will be well suited for precision tests of the standard model. QCD corrections to the asymmetry are particularly small on top of theZ ⁰, with the leading terms induced by quark mass effects. The influence of initial state radiation inA _LR is essentially accounted for by a slight shift in beam energy. Initial/final state QED bremsstrahlung interference (QED boxes) is studied in detail and its influence onA _LR is found to be negligibly small, especially close to the top of theZ ⁰ peak. A comment on the importance of helicity nonconservation for polarized beams in the presence of photon emission is also included.     

THE REGGE TRAJECTORY OF MESONS AND THE SU(4) MASS RELATIONS

A relativistic equation of motion of a two particle system under the constraints p_i²-m_i²-U(x²)=0.(i=1,2), where U(x²) is an infinite spherical square well poten-tial, is applied to the SU(4) quark model of mesons. A set of linear mass relations areobtained. Instead of the linear relation between J and M², the Regge trajectory ob-tained is a relation between p_nl² and M², where ζ_nlπ are zeros of the spherical Besselfunctions. The new trajectory seems more satisfactory than the former one.     

THE POSSIBILITY OF ξ(2.22) BEING THE STANDARD HIGGS BOSON

We discuss the possibility that the new particle ξ(2.22) is a mixed state of the Higgs boson of the minimal electro-weak model and the p-wave charmonium χ(3.415). If this possibility stands, we shall have Γ_ξ=1.1 keV, Br(ξ→K+K^－)～1/5 and a heavy quark (m>75GeV).     

凝聚炸药中超压爆轰的实验研究

 采用飞片碰撞技术，在TNT/RDX（40/60）炸药中获得了2.5倍于正常爆轰的最大超压值，得到了超压爆轰下爆轰产物物态方程p=Aρ^{k+A₁(p-p_J)}（p－爆压，单位GPa，ρ－密度，单位kg/m³，A=ρ_J/ρ^k_J，p_J=27.06 GPa，ρ_J=2.3×10³ kg/m³，k=2.77，A₁=2.7×10^-3 GPa^-1，下表J代表正常爆轰状态）。该方程还可以较好地描述超压爆轰产物的二次冲击状态。