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1.
We discuss the suppression of the decay of heavy lepton τ into πvτ,by assuming that τ and/or vτ carry spin 3/2. For the case of spin 3/2 T and spin 1/2 vτ, using the weak current ψμ(τ)(a+bγ5)Ψ(vτ)we find that the πvτ decay channel relative to the vτvll-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.  相似文献   

2.
We give an approximate sequence for Ut,t0)-operator.We prove the follow-ing theorems:Theorem 1.If the norm ||Ht)|| of Ht)in equation(2.1)is a Lebesgue in-tegrable function with respect to t,then there is an approximate sequence{Un},such that for any state vector |Φ〉,|Ψ〉,the sequence <Φ|U1|Ψ><Φ|U2|Ψ>,......,<Φ|Un|Ψ>,......is uniform convergent with respect to t.Theorem 2.If in finite time interval,the norm ||Ht)|| of Ht)in equation (2.1)is a Lebesgue integrable function,then equation(2.1)has unique solution.  相似文献   

3.
本文证明了以下结果:虽然单粒位阱 uαβ=Mαβ(εβ)[或 uαβ=Mαβ(εα),Mαβ(ω)为质量算符]是非厄米的,但由它所确定的断续本征值εγ却一定是实的,而且严格满足以下关系:εγ,=±[E(N±1)—E0(N)]其中 E0(N)与 E(N±1)分别表示满壳核(核子数为 N)基态与(N±1)核的严格能量本征值.此外,为了判断任一单粒位阱的本征值是否也可能满足上述关系,文中给出了一个计算其判据的简便方法.应用这方法还可很容易地算出单粒格林函数的振幅修正.  相似文献   

4.
In this paper, the possibility that the newly discovered heavy particle γ (9.5) is a colour excited state of mesons in the SU(4)×S3α scheme of straton model is discussed. We point out that in the γ region, there are three colour excited states appearing as two peaks with mass difference about 0.5 GeV. The leptonic decays, hadronie decays, radiative decays, hadronic decays with electromagnetic interaction of the second order and the production behavior of γ are discussed. This model also predicts that many colour excited states of mesons accompanied with γ should exist with masses around 9.5 GeV and at least four weakly decaying particles should exist.  相似文献   

5.
The excitation functions of the 23Na(p,α020Neg·s.and the 23Na(p,α120Nelst reae-tion have been measured from Ep=1 to 2.5 MeV at θL=30°,150° and 30°,respectively.Around the resonance at 2.171 MeV,the excitation functions of the(p,α0)reactionhave been measured at 12 angles,then,some angular distributions have been obtained from these excitation functions.In addition,the angular distribution of the(p,α0)reaction for the resonance at 2.171 MeV has also been measured directly at energy ofthe resonance peak of the excitation function at 150°.For the resonance at 2.117MeV,the angular distribution have been measured at two energies,one at the energyof the resonance peak of the excitation function at 150°,another at the energy of thehalf maximum point of the resonance peak on the higher energy side.Around the re-sonance at 2.075 MeV,the excitation functions have been measured at 16 angles,andthe angular distribution has been obtained from three excitation functions.The an-gular distributions of the three resonances are not symmetric about 90°,and the posi-tions of the resonance peaks of these resonances varies with the angle of measurement.By means of the compound nucleus theory,discussions have been made for these non-solated resonances.  相似文献   

6.
The preliminary results of big family events obtained by emulsion chamber experiment at Mt. Kanbala are presented. General feature of γ-ray familes with ΣEγ≥1000TeV are discussed and compared with the Monte Calo simulation.  相似文献   

7.
In this paper, the matrix elements of the nucleon-meson vertices due to one gluon exchange transition potential Vq→qqq are calculated by using the generator coordinate method. We obtain that the interaction forms of the vertices are the same as the nonrelativistic forms coming from the interactions of the nucleon field and the meson field; and the coupling constants are roughly consistent with the experimental data.  相似文献   

8.
In this paper, we propose an SU(4)×S3a scheme of the Straton Model and discuss the classification of mesons. We suggest the possible existence of several colour excited states with masses around 2 GeV in companion with charm mesons. We also discuss the properties and the experimental behavior of these colour excited states, especially, the possible contribution of these states in several new phenomena.  相似文献   

9.
In this note,we discuss the cross-sections of the production of Υ particles in p-p collisions as color excited states in the Han-Nambu model.The results are consistent with present experiments.  相似文献   

10.
In this Paper a calculable three-body T matrix with compact kernel is obtained by using multiplier's methods. The formulations for calculating the A(a, ax)B type three-body reaction trans-tion amplitudes are presented when plane wave or distorted wave is used for the incident and outgoing states. This T matrix also includes the resonance terms of the three-body chain struc-ture states besides quasi-free scattering terms and final states interaction terms. A calculable formulation for the resonance energy of chain structure states is presented when it is expanded approximately into two two-body bound states. For 8Be and 6Li as target nuclei, the resonance energies are calculated. The results are in good agreement with the experimental values and the theoretical values of a mole-cule-like model. In order to check this kind of resonances, some experiments are proposed.  相似文献   

11.

We analyse the necessity and possibility of introducing an axial vector piece into the effective potential in order to cancel the spin-orbit interactions and the problems related thereby.

  相似文献   

12.
用固相反应法制备(1-x)La0.6Dy0.1Sr0.3MnO3/x/2(Sb2O3)(x=0.00,0.02,0.15)样品,通过X射线衍射(XRD)图谱,扫描电子显微镜(SEM)照片及SEM能谱(EDS),ρ~T曲线研究样品的结构及电输运性质.结果表明:Sb离子没有进入Mn位,Sb2O3包覆在La0.6Dy0.1Sr0.3MnO3颗粒表面,Sb2O3起助熔剂作用,使得复合样品的颗粒变大且大小相对均匀;复合样品的绝缘体-金属转变温度TP较纯的La0.6Dy0.1Sr0.3MnO3的TP提高20K左右,对x=0.15的样品电阻高峰值比纯的La0.6Dy0.1Sr0.3MnO3的峰值电阻率增大两个数量级,用自旋极化隧穿理论予以解释.  相似文献   

13.
Some discussion is made for the angular momentum difference i(ω) introduced byA. Bohr and B. Mottelson.  相似文献   

14.
Calculations have been performed for the energy separation of the two major substitutional states of the hypernucleus 40ΛCa. The (K) cross sections are calculated in the framework of the distorted-wave impulse approximation. Information about the ΛN interaction is then extracted, particularly, on the effects of the strength parameters on cross sections. The result shows that the ΛN interaction adopted previously for the 1p shell hypernuclei might be suitable to use for the (K) reaction in which medium heavy hypernucleus 40ΛCa are produced, but the value for the strength parameter of the central potential has to be changed from 0.99 to 0.78.  相似文献   

15.
LD泵浦Nd3+∶GdVO4/Cr4+YAG固体激光器   总被引:4,自引:4,他引:0  
周城  张仲  赵朋  张中士  张莉 《光子学报》2006,35(6):801-803
通过合理设计,精密调控各元件和温控电流,得到了平均功率为70mW,脉冲宽度为22ns,重复频率为14 kHz,峰值功率高达230 W的Nd3+∶GdVO4/Cr4+YAG绿光脉冲激光器.腔外采用望远镜系统聚焦,经KTP晶体倍频后,得到了平均功率为28.8 mW,脉冲宽度为19 ns,重复频率为14 kHz,峰值功率高达108 W的绿光激光输出,转换效率高达.指出了小光斑对倍频晶体带来的影响.  相似文献   

16.
In this paper the π condensation effects in finite nuclei are investigated. We have supposed a model hamiltonian, and have calculated the eigensolution in the Random Phase Approximation. The energies and the π condensed number of the graund state and the one phonon excited states are obtained. The results are discussed for the case of 16O.  相似文献   

17.
用机械合金化方法制备了(FeAl3)75Zr25和(FeAl3)50Zr50非晶态合金,用X射线衍射仪和热分析仪对制备的非晶态合金的结构特性及热稳定性进行了研究,用振动样品磁强计对(FeAl3)75Zr25和(FeAl3)50Zr50混合粉末在机械球磨过程中的磁性变化进行了研究,并对其晶化产物及其晶化后合金的磁性进行了分析。结果表明:(FeAl3)75Zr25的晶化产物为Fe3Zr和Al1.65Fe0.33Zr;(FeAl3)50Zr50非晶态合金的晶化产物为FeZr2和AlZr2。(FeAl3)75Zr25混合粉末的矫顽力随着球磨时间的增加而增加,但其饱和磁化强度和剩磁均随着球磨时间的增加而下降。而(FeAl3)50Zr50混合粉末的矫顽力、饱和磁化强度和剩磁均随球磨时间的变化则没有类似的规律性。晶化后(FeAl3)75Zr25粉末与(FeAl3)50Zr50粉末相比,前者矫顽力小,但饱和磁化强度和剩磁大。  相似文献   

18.
Quasi-classical trajectory theory is used to study the reaction of O(3 P) with H 2 (D 2) based on the ground 3 A″ potential energy surface (PES).The reaction cross section of the reaction O+H 2 →OH+H is in excellent agreement with the previous result.Vector correlations,product rotational alignment parameters P 2 (j · k) and several polarizeddependent differential cross sections are further calculated for the reaction.The product polarization distribution exhibits different characteristics that can be ascribed to different motion paths on the PES,arising from various collision energies or mass factors.  相似文献   

19.
In this paper the nonleptonic D0-decays are discussed. Using Gilman and Wise's methods, we derived the effective Hamiltonian for Cabibbo-suppressed nonleptonic D0*-decays. The rate F(D0→K+K-)/Γ(D0→π+π-)~1.26 is obtained. Some problems in this method of the calculations are discussed roughly.  相似文献   

20.
The energy spectra and angular distributions of alpha particles emitted in the reaction of 12C on 209Bi in the energy range 61.1—73.0 MeV were observed.The △E— E detector system was used to separate alpha particles and other particles emitted in this reaction.The results can be interpreted in terms of the reaction mechanism,in which a 8Be cluster is transfered from the projectile to the target.Good agreement has been obtained between the cross section for the production of the direct alpha particles and that of the heavy residue 217*Fr which,left in the ground state after evaporation of 2 neutron's,decays into 211At by alpha emission.The experimental energy spectra and angular distributions have been fitted by a semi-classical formula for the differential cross section per unit solid angle and energy interval.  相似文献   

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