AN SU(4)×SU(2)×U(1) UNIFIED MODEL

In this paper we propose an SU(4)×SU(2)×U(1) unified model, in which the stratons and leptons of every generation belong to the same Multiplet, and the leptons will couple to the stratons. But this kind of coupling cannot cause the proton decay, and has only some effects in high energy scatterings. This model predicts the existense of two neutral intermediate bosons, instead of one, and the value of Weinberg angle to be sin²θ_w=0.25. The neutrinos have reasonable masses in the model.     

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.     

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.     

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.     

WAVE FUNCTIONS WITHOUT SU6 SYMMETRY IN THE STRATON MODEL AND THEIR APPLICATIONS

On the basis of the straton model^[1],using the general groundstate wave functionsof mesons and baryons given in ref.[2],we have constructed under some specific as-sumptions the meson and baryon wave functions without SU₆ symmetry.We applythese wave functions to explain the mesonic and baryonic properties of the electroma-gnetic and weak interactions;many results obtained are in agreement with the experi-ments.By using the 1/2⁺-baryon wave functions without SU₆ symmetry,we obtain ananomalous magnetic moment for the proton.There is no need to introduce an ano-malous magnetic moment for the straton in the effective Hamiltonian of electromag-netic interaction between stratons.Similarly,the magnetic moment of the neutroncan also be explained.     

One Loop PGBs Effects on tt Production in High Energy e+e- Annihilation

The Technicolor(TC)O(αm_t²/m_w²)corrections to top pair production in high energy e⁺e^－ annihilation are calculated in the one generation TC model.The analytic expressions are given for the form factor, the renormalized matrix element and its square.Numerical examples are presented for the corrections to the total cross-section ,the forward-backward asymmetry A_FB and the left-right asymmetry A_LR.We found that the corrections can reach －12.3%, －3.3% and －11.7% to the observables,A_FB and A_LR respectively for the favorable parameter values.The level of these corrections might be achieved at the next-generation linear collider(NLC).It might open a window for testing TC theory.     

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)%.

     

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.     

UNIFIED ELECTRO-WEAK MODEL IN SU (3)

In this paper a unified electro-weak model for leptons based on the SU(3) gaugegroup is suggested by means of four kinds of realization for the generators of thegroup. For all low energy electro-weak processes, this model predicts the same resultsas the conventional Weinberg-Salam model does. The Weinberg angle is shown to be sin²θ_w=1/4 in a natural way. When the Higgs self potential respects a discrete symme-try Φ→-Φ, a new conserved quantum number called weak strangeness emerges fromthe model after spontaneous symmetry breaking. In the present model there existanother four heavy vector gauge bosons V^± and U^±± together with some heavyfermions and Higgs scalars, which have non vanishing weak strangeness quantumnumbers. These weak strange particles have no direct couplings with leptons. Theirexistence will not influence the low energy electro-weak processes. Nevertheless, theycan be produced in pairs in high energy collisions and the lightest of them should bestable if the conservation of weak strangeness is exact. The experimental implicationsand the possibility of violation of the conservation of weak strangeness are also dis-cussed.     

AN SU(6) GRAND UNIFIED MODEL

A model of grand unified theory based on SU(6) gauge group is proposed. It can accommodate two generations of ordinary fermions with V－A weak coupling and two generations of anomalous fermions with V+A weak coupling. In this model a new discrete symmetry is introduced which insures existence of fermions with lower masses when SU(6) gauge symmetry is spontaneously broken. We choose simple Higgs fields with appropriate vacuum expectation values so that the masses of anomalous fermions are heavier than those of ordinary fermions. This model also gives the same value of Weinberg angle, sin²θw=3/8, as in the usual SU(5) grand unified model at the grand unified scale.     

DISCRETE SYMMETRY AND SU(N) GRAND UNIFIED MODELS

Using discrete symmetry S, a systematic analysis of all possible GUT models based on the low rank group SU(N)×S is presented. It is found that only SU(7)×S and SU(8)×S are the satisfactory gauge groups of flavour grand unification. In addition, SU(7)×S and SU(8)×S models are discussed in detail. All these models can accommodate. four generations of ordinary fermions and preserve the asympotic freedom of SU_c(3).     

SU(3) LEPTON MODEL AND THE DYNAMICAL GENERATION OF LEPTON MASS DIFFERENCES

A SU (3) lepton model is discussed in which the left- and right-handed leptons are on equal footing and sin²θ_w=1/4 is obtained. Dynamical symmetry breaking is investigated to see if lepton mass difference can be generated in this way so as to reduce the number of Higgs scalars and Yukawa coupling constants. Calculating the effective potential up to two-loop graphs gives the results that composite Goldstone bosons can exist only when the remained Yukawa coupling constant lies within a certain range. The corresponding heavy lepton mass obtained is about 130 GeV.     

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.

     

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.     

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.     

ON THE IRREDUCIBLE REPRESENTATIONS OF THE COMPACT SIMPLE LIE GROUPS OF RANK 2(I)

In this paper, we analyse the commutation relations of the infintesimal opera-tors of the group SU₃ and find that the eight infinitesimal operators of the groupSU₃ can be written as a scalar operator A, three angular momentum operators (L₁,L_o, L_-1,)and two sets of the irreducible tensor operators of rank 1/2, （T_±1/2,V±1/2）By means of the commutation relations of these operators, all irreducible represen-tations of the group SU₃ can be easily obtained. In this pape, the matrices corresponding to these operators in the irreduciblerepresentation（λμ）, are given; therefore the irreducible representation and its re-presentation space R^λμ are completely defined. Besides, a method for calculatingthe scalar factors of the reduction coefficients and the symmetric relations of thosefactors are also given. As examples, the scalar factors of the reduction coefficientsof （λμ）×（10）, （λμ）×（01）, （λμ）×（20） and （λμ）×（11） are calculated. In the last part of this paper, we define the irreducible tensor operators ofthe group SU₃ and prove the corresponding Wigner-Eckart theory. The method used in the discussion of the group SU₃ be extended to allof the compact simple Lie groups of rank 2 and we shall discuss them in two suc-ceeding papers.     

THE SPECTROSCOPY OF FOUR-BARYON SYSTEM

In this paper, using SU(6) symmetry theory four-baryon system is discussed and a method of analyzing experimental spectra is provided. Because of the gound states of _ΛΛ⁴H, _ΛΛ⁴He_{, Λ}⁴He and ⁴He are in the same I. R. of SU(6), on can derives masses for _ΛΛ⁴H, _ΛΛ⁴He from the experimental data of _Λ⁴H, _Λ⁴He, and ⁴He. Calculation shows that these J^π=0⁺ double Λ hypernuclei _ΛΛ⁴H, _ΛΛ⁴He are not likely bound states.     

Quark-Chiral Field interaction in SU(3) Model

A quark-quark potential is derived from the linear expression of the Lagrangian Which is invariant under the SU(3)_L×SU(3)_R infinitesimal transformation,and further used to make a qualitative analysis on the Λ-N interaction.The result shows that the SU(3)chiral scalar fields are important in explaining the spin-dependence feature of the Λ-N interaction.     

THE SU2×SU2 BASIS AND THE PHYSICAL BASES FOR THE STATE VECTORS OF d-BOSON SYSTEMS AND THE TRACELESS BOSON OPERATORS (Ⅰ)

The group chain U₅O₅SU₂×SU₂ used by K. T. Hecht (1965) and by the othersprovides an important representation for expressing the physical basis of d-boson sys-tems. However the methods which have been introduced for this SU₂×SU₂ representa-tion to construct a physical basis is poorer in comparison with those for the otherrepresentations. In view of this we try to find appropriate methods to obtain the SU₂×SU₂ representation wave functions of the existing physical bases constructed byChacon et al. and by Szpikowski et al., In the present paper we analyse the SU₂×SU₂ tensor properties of the,bosonoperators and Vilenkin's traceless boson operators and express succinctly the elementaryvectors of the SU₂×SU₂ basis, the |PP SU₂×SU₂ > vectors, in terms of the tracelessoperators. With the help of this form of the| PP SU₂ SU₂> vectors we derive a simpleformula for obtaining the SU₂×SU₂ -representation wave functions of a physical basisfrom its (n_μ)-representation wave functions. Thus the problem mentioned above is partlysolved. The other parts of the solution of the problem will be found in a coming paper.