共查询到20条相似文献,搜索用时 15 毫秒
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Based on the most important "hard" production mechanism,the production rate of Bc(or Bc) meson being accompanied with one c(or c) and one b(or b) heavy quark jets through Z0 decay is computed in this paper.It is pointed out that at LEP up to next run,quite a lot of events with one Bc or Bc meson may be obtained,so that it becomes accessible to study the properties of Bc and Bc mesons throngh Z0 decay experimentally. 相似文献
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Using the definition of irreducible tensor operators of the Lie group SU(n), we ive a method of calculating the irreducible representations of the graded Lie algebra U(m/n). We also give some simple examples of irreducible representations of U(3/2) and SU(m/n). 相似文献
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YU SHOU-MIEN 《中国物理C(英文版)》1982,6(1):36-43
A relativistic equation of motion of a two particle system under the constraints pi2-mi2-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 pnl2 and M2, where ζnlπ are zeros of the spherical Besselfunctions. The new trajectory seems more satisfactory than the former one. 相似文献
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The general one body E2 operator is used to derive the analytic expressions of B(E2) from the first β and γ bands to the ground band under the SU(3) basis. 相似文献
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THE DOUBLEDELTA AND THE SURFACE DELTA INTERACTIONS AND SPECTRA OF OXYGEN ISOTOPES IN THE (s-d) SHELL 下载免费PDF全文
By using the Double Delta Interaction (DDI) and the Modified Surface Delta Interaction (MSDI) as the effective interaction respectively and by the mixed-configuration, the low-lying spectra of oxygen isotopes 17-22O in the (s-d) shell space are calculated. The results are favourable for DDI.
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THE PARTIALLY VIOLATED U(3) LIMITS OF THE DYNAMICAL SUPERSYMMETRY U(6/12) IN EUROPIUM-GADOLINIUM REGIONS 下载免费PDF全文
SHAO Yi-Ping 《中国物理C(英文版)》1987,11(3):392-396
The partially violated U(3) limits of the U(6/12) model is presented. The theoretical predictions are compared with existing experimental data of energy spectra and B(E2). The theory tallies with experiment fairly good. 相似文献
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We discuss the CP violation problem of SU(7) models of Grand Unified Theoryincluding four genarations[1,2]. It is shown that if we properly choose the complex phaseangles in quark mass matrix elements, we are able to obtain the CP violation phaseangle which agrees well with the experimental value. If the Higgs potential is pro-perly choosen we find that the strong CP violation parameter θ is equal to zero atthe tree level. 相似文献
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A simple method is proposed to obtain the classical monopole and dyon solutions in the case of SU(4) symmetry, which can be systematically generalized to the general case of SU(N). The solutions obtained in the SU(4) case correspond to magnetic charges of ±1/g,±√3/(2g),±1/(√2g). 相似文献
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The SrZnP2OT:Eu^2+, Mn^2+ phosphor is synthesized by high temperature solid state reaction. The luminescence properties and the energy transfer between Eu^2+ and Mn^2+ are investigated. The emission bands of this phosphor peaked at 42Ohm and 67Ohm are originated from the 5d → 4f transition of Eu^2+ and from the 4T1 (4G) --〉 6A1 (6S) transit/on of Mn^2+, respectively. With the increasing Mn^2+ concentration, the intensity of fixed concentra- tion Eu^2+ decreases and the intensity of Mn^2+ also increases. It is suggested that there is an energy transfer from Eu^2+ to Mn^2+ in SrZnP2O7 host. According to Dexter's energy transfer formula of multipolar interaction, the energy transfer between Eu^2+ and Mn^2+ is due to the electric dipole-quadrupole interaction of the resonance transfer. 相似文献
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KUANG YU-PING 《中国物理C(英文版)》1981,5(1):72-81
A SU (3) lepton model is discussed in which the left- and right-handed leptons are on equal footing and sin2θw=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. 相似文献
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Scintillation properties of YPO4: RE (RE=Ce3+, Pr3+ or Nd3+) 总被引:1,自引:0,他引:1
The spectra of RE-doped YPO4 (RE=Ce3+, Pr3+ or Nd3+) have been measured. The spectroscopic and decay kinetics properties of pure host YPO4 were also studied at 8 K and 300 K, which indicated the host had taken part in the luminescent processes of activators. Under the excitation over the bandgap of the host, the electron could relax to the activators. Through the comparison of spectra and decay time, Nd3+ doped YPO4 had better scinillation properties than Ce3+ or Pr3+ inYPO4. 相似文献
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本文叙述了Yb-Ba-Cu(O,F)体系超导体的制备,点阵常数、单胞体积以及Tc随F加入量和O含量的变化。实验结果表明,在YbBa2Cu3O7-x-δF2x(0≤x≤1)体系中,O含量越低,Tc越高,点阵常数和单胞体积就越大。晶体结构分析结果证明点阵常数a与b的差值愈大的正交相结构,其超导性能愈好,表明一维Cu-O链结构对高Tc超导机制有重要作用。
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Co2+:ZnAl2O4晶体电子光谱及其2E态双重谱线结构的Jahn-Teller效应研究 总被引:5,自引:3,他引:2
在中间场耦合图象中,利用Racak不可约张量算符法和Wigner-Eckart定理,建立了3d7(C3v)电子组态的完全能量矩阵;利用该矩阵研究了Co2+:ZnAl2O4晶体的电子光谱,理论与观测十分吻合.首次定量地解释了2E态的双重谱线结构,并从理论上预言了4A2基态2.93cm-1的零场分裂(ZFS).研究结果定量地表明,Jahn-Teller效应所致Co2+:ZnAl2O4晶体Co2+中心局域结构的畸变假设是合理的. 相似文献
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利用低能N+(0.5keV)离子轻微轰击2H-MoS2(0001)清洁表面,从UPS(HeⅠ,HeⅡ)得到d电子峰向EF移动,价带顶出现明显的“肩膀”或带尾,它随轰击时间的增加而增强,同时使d(z2)带变宽。UPS的结果表明,这种表面在室温下有明显的O2吸附活性,O2吸附后这个肩膀明显下降。结合XPS,AES和LEED的研究,我们认为这个“肩膀”态与次表面原子层的Mo原子的d电子的暴露和最外表面原子层s原子空位缺陷的产生有关。这些新的表面电子态与加氢脱硫(HDS)催化活性中心有密切的关系。
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根据文献[1]中给出的模型和能隙方程,计算了超导态的热力学临界磁场,Tc处的比热跃变以及Tc以下的比热行为。结果表明:有关热力学量的临界值与实验结果定性相符;Tc以下的比热行为在整个温区与CeCu2Si2和UBe13的实验结果符合。
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YU Zu-Rong 《中国物理C(英文版)》1983,7(1):121-125
In this note, we have given a method of calculating the transformation coefficients between SO(6) and SU(4) Gelfand Zetlin states. 相似文献