MEASUREMENT OF THE ENERGY SPECTRUM OF PRIMARY COSMIC PAYS

The method and arrangement determining the energy spectrum of primary cosmic rays by measuring the Cerenkov radiation were described. The integral power index γ=1.80±0.11 of energy spectrum of primary cosmic rays wa measured at the energy range of 2.9×10¹⁴－4.0×10¹⁵eV.     

THE POSSIBILITY OF EXITENCE OF NEW ISOTOPE 65Se

A new beta-delayed proton precussor ⁶⁵Se has was probably produced via the reaction ⁴⁰Ca (²⁸Si,3n)⁶⁵Se and identified from its beta-delayed proton emission.A single proton group at 3.75±0.05MeV with half-life of 10.8±4.1/3.7ms was observed,corresponding to superallowed beta decay of ⁶⁵Se to the isobaric analog state of ⁶⁵As (the lowest T=3/2 state in ⁶⁵As) then proton emitting to the ground state of ⁶⁴Ge.Because of poor statistics further experimental effort is required to confirm this discovery.     

THE CROSS SECTION MEASUREMENT FOR THE 107Ag(n,2n)106mAg REACTION

The cross section for 107Ag(n,2n)^106mAg has been measured by using the activation method relative to the cross section of ²⁷Al(n,α)²⁴Na in the neutron energy range of 13.50—14.73MeV.The values of 469±22,480±22,503±24,538±25,555±25,572±26mb were obtained at the 13.50,13.60,13.90,14.10,14.35,and 14.73MeV neutron energy,respectively.The results are compared with the published data.The neutron energies were determined by activity ratios of Nb and Zr foils.     

ANALYSIS OF THE E2 TRANSITIONS BETWEEN THE d+a CLUSTER STATES OF 6Li WITH THE RGM

The E2 reduced transition probabilities between the d-a cluster states of ⁶Li were calculated by the RGM in this paper.The resulting B(E2;E₁→E₀)=21.06fm⁴ consistented with the experimental value 25.1±2.0fm⁴ more than the calculated values of the double-well cluster model including p-state exciting and LCCO.Also,the B(E2;E₃→E₀)=9.67fm⁴ coincided with the exprimental value 6.483±3.360fm⁴ within the error range.     

Isospin Effect on Relative State Population Temperature in the Reactions 40Ar+ 112,124Sn at 30MeV/u

An array of 13 detector telescopes has been used for detecting small-angle particle-particle correlations in the reactions ⁴⁰Ar+^112,124Sn at 30MeV/u. The α-α correlation functions were extracted from two-particle coincident events. A three-body trajectory code MENEKA was used to calculate the background correlation function. The detection efficiency was calculated by using the Monte-Carlo method. After subtracting the background correlation and making the detection efficiency correction, the temperatures of 4.18±0.25 0.21 MeV and 4.10±0.22 0.20MeV are obtained from relative populations of ⁸Be states for the reaction systems with different isospin,⁴⁰Ar+¹¹²Sn and ⁴⁰Ar+¹²⁴Sn, respectively. From the relationship between the state population temperature and outgoing particle energies, it is found that the emission temperature decreases with increase of the particle energies for both studied reaction systems. For the neutron deficient system ⁴⁰Ar+¹¹²Sn the emission temperature is 5.13±0.30 0.26MeV for the lower emitting particle energies and 3.87±0.37 0.29MeV for the higher emitting particle energies. And for the neutron rich system ⁴⁰Ar+¹²⁴Sn the emission temperature is 5.39±0.30 0.26MeV for the lower emitting particle energies and 3.32± 0.28 0.23MeV for the higher emitting particle energies. This kind of isospin dependence is discussed.     

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.     

Measurement of Structure Function of τ→π±2π0v

The structure function of τ→π^±2π⁰v is measured by model independent method. The result is compared with Kuhn-Santamaria model, Isgur-Morningstar-Reader model and Feindt model. Good consistency between data and the three models is shown within the experimental error range. The comparison with the structure function of τ→3π^±v measured by OPAL Collaboration also shows there is no obvious difference within 0.52.     

Measurement of Inclusive Semileptonic Branching Fractions for D－→e－X and D0→e－X

We report a measurement of the absolutely inclusive semileptonic branching fractions of D^－ and D⁰ mesons, using a data sample of 22.3pb^－1 collected with BES detector at BEPC e⁺e^－ Collider at s=4.03GeV and based on the method of "combinative D⁺ and D⁰ single and double tags". The measured values of the branching fractions for D^－→e^－X and D⁰→e^－X are (21.8±8.5±4.2)% and (8.9±3.0±1,6)%, respectively. The measured ratio of the branching fractions is BF(D^－→e^－X)/BF(D⁰→e^－X)=2.4±1.7±0.8.     

0－ Heavy Meson Bound States at Heavy Quark Expansion

0-heavy meson bound states are discussed by using the Bethe-Salpeter (B-S)equation at the instantaneous approximation. In terms of the heavy flavor mass expansion method, the masses for mesons D⁰, D^±, B⁰, B^± are calculated at first order approximation. Comparisons of our results with experimental data and with some theoretical calculations from other method are given.     

A CLASSICAL MODLE OF QUANTUM BERRY'S PHASE FACTOR

Considering that the classical evolution equations are similar to the Schrodinger eqaution,we point out that there is the structure of the Berry's Phase in the solution of a classical evolution eqaution with adiabatic changing parameters.Thus,we can use a classical evolution process to imitate the quantum adiabatic process.As an example,the motion of a charged particle in slowly-changing magnetic field is studied and the corresponding phase factor can be interpreted as a holomony of the fiber bundle on the sphare s² in the parameter space.     

Experimental Study of Hadron Inclusive Production in J/ψ Region

The mean multiplicities of mesons π^±、π⁰、K^±、K⁰_s、ρ⁰.K^*0、K^*±、φ and baryons p、Ξ^±、Σ^±(1385) are measured for the first time in J/ψ region with 200,000 J/ψ events collected by the BES detector. The results are compatible with LUND and Shandong phenomenological models. Based on the experimental results, the strangeness suppression factor s/u and spin suppression factor V/(V+P) are calculated to be ～0.3 and ～0.3—0.5 respectively, in good agreement with those given by ARGUS Collaboration in region. This indicates that the SU(6) breaking is consistent in the energy region from J/ψ to .     

EXCITATION CURVES FOR SOME REACTIONS OF Al、Ti、V AND I

Excitation curves for the reaction ²⁷Al（n,α）²⁴Na,⁴6Ti（n,p）⁴⁶Sc,⁴⁸Ti（n,p）⁴⁸Sc,⁵¹V（n,α）⁴⁸Sc and ¹²⁷I（n,2n）¹²⁶I have been measured by the activation method in the4.5—18.3 MeV energy region.The cross section for the reactio ²⁷Al（n,α）²4Na was determined at 14.61±0.20 MeV.The measurement of neutron flux was performed using the associated particle method.The cross sections for other reactions were de-termined relative to the measured ²⁷Al（n,α）²⁴Na cross section.The resulting activities were measured employing a calibrated NaI（TI）scintillation counter.The values obtained were 117.5±3.0 mb,291.4±14.0mb,63.7±3.2 mb,16.8±0.9mb and 1656±68 mb respectively.A brief comparison with existing data was made.     

Decay of the J/ψ to Σ0Σ0 Final State

With 7.8 million produced J/ψ events collected by the BES detector at the BEPC, the decay J/ψ→Σ⁰Σ⁰ is analysed. The branching ratio is measured to be BR(J/ψ→Σ⁰Σ⁰)=(0.97±0.04±0.24)×10^－3. The angular distribution is of the form dN dcosθ=N₀(1+α cos²θ) with α value of －0.21±0.27±0.13.     

CROSS SECTION MEASUREMENT FOR THE REACTION 56Fe（n,p）56Mn

The cross section measurement for the reaction ⁵⁶Fe（n, p）⁵⁶Mn was made using the activation method from 12 MeV to 18 MeV. The absolute cross section was determined at 14.61±0.20 MeV, the value obtained was 108.0±2.7mb. The associated particle method was used to determine the absolute neutron flux and compared with the recoil proton telescope. The agreement between both methods appeared to be within 1—2%. The resulting ⁵⁶Mn activity was measured by using a φ10×7.6cm NaI （Tl） scintillation counter. The counting efficiency of the counter was achieved by means of a standard ⁵⁶Mn source calibrated by the 4πβ-γ coincidence method. The result measured was compared with existing data.     

Experimental Study on 22Na(p,γ)23Mg Reaction

The reaction of ²²Na(p,γ)²³Mg has been investigated at the Radioactive Ion Beam Line in Lanzhou(RIBLL) using a radioactive beam ²³Al. The β⁺ delayed proton decay spectrum has been measured with the TOF-ΔE method and zero degree detectors. The half life of ²³Al is determined to be T_1/2=(476±45)ms by using a time scaler combined with the precision pulse generator,which is consistent with the other group's result of (470±30)ms. The known β⁺ delayed protons at E_r=0.216,0.278,0.438,0.479MeV have also observed in the experiment. The resonance strength of isospin analog state (IAS) is calculated. The resonance intensity of IAS is (11.4±6.0)meV. A new energy level of β⁺ delayed proton decay has been identified at E_x=8.916MeV,and their relative intensity also been obtained.     

ON THE POSSIBILITY OF W,Z AS COMPOSITE PARTICLES

The relation between the masses of W^± and Z⁰ in a composite model is disscused phenomenologycally. It is shown that any deviation of experimental data from the predicted value of W-S model will be in favour of the composite model.
By using present experimental data, the calculation results show that is W' (the radial excited state of W) exists, then its mass will be greater than (2—5)m_w.     

A Monte Carlo Study of the Fractal Property inside Jets Produced in High Energy e+e－ Collisions

The anomalous scaling property inside jets produced in e⁺e^－ Collisions at s91.2GeV is studied using Monte Carlo method. A new variable r is applied, which has very good anomalous scaling property. The relation between the scaling indices of different orders is investigated. The Lévy index for the hadronic system inside jets is obtained, which turns out to be μ=2.498±0.025, very close to the same index of hadron-hadron collisions. On the contrary, the Lévy index of e⁺e^－ collisions is 1.701±0.043, being less than 2. Since the multi-hadron production in e⁺e^－ collisions is dominated by hard gluon emission or hard parton branching, while the parton fragmentation into jet, like the multi-production in hadron-hadron collisions, is a soft process, the above results suggest that the value of Lévy index may provide another signal for the qualitative difference between hard and soft processes.     

Measurement of the τ Polarization Asymmetry in τ→a1 v→π±π0π0v Decay at Z0 Peak

The τ polarization asymmetry in τ→a₁v→π^±π⁰ π⁰v decay at Z⁰ peak is measured using data collected by L3 detector at LEP in 1992 and 1993, A_pol=－0.239±0.126±0.100, where the first error is statistical and the second systematic. And the effective electroweak mixing angle sin²θ_w=0.2197±0.0219 is derived.     

ΛΛ,ΛΛγ and ΛΛπ0 Productions in J/ψ Decay

The channels of J/ψ decay into,ΛΛ,ΛΛγ and ΛΛπ⁰ are analyzed with 7.8×10⁶ J/ψ events collected by BES detector at BEPC Collider.The branching ratios for three channels and the angular distribution for the first channel are measured.The branching ratios are Br(J/ψ→ΛΛ)=(l.08±0.06±0.24)×10^－3,Br(J/ψ→ΛΛγ)－4(90% CL)and Br(J/ψ→ΛΛπ⁰)=(2.3±0.7±0.8)×l0^－4 respectively. The angular distribution for J/ψ→ΛΛ is dN dcosθ=N₀(1+αcos²0),α=0.52±0.33±0.13.     

Structure Analysis of the l/η(1440)

By an amplitudes analysis of the KKπ system in the J/ψ radiative decay to the K⁺K^－π^O and the K⁰_SK^±π⁺ final states, we find that there is one 0^－+ resonance (M=1467±3MeV,Γ=89±6MeV) and two 1⁺⁺ resonances (M=1435±3MeV,Γ=59±5MeV and M=1497±2MeV,Γ=44±7MeV), Which are consistent with the η(1440), the f₁(1420), and the f₁(1510).