共查询到20条相似文献,搜索用时 140 毫秒
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利用在北京正负电子对撞机上北京谱仪采集的3.6×106 ψ(2S)事例,测量了ψ(2S)新的强子衰变道ψ(2S)→ρα2和K*0K2*0+c.c.的分支比,发现二者相对于J/ψ的相应衰变道明显压制,破坏了微扰QCD理论预言的“15%规则”,从而继前已报道的ψ(2S)→ωf2确认了另外两例末态为矢量与张量介子的ψ(2S)反常衰变. 相似文献
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利用BES上取得的9.0×106 J/ψ数据,进行了系统的J/物理分析.证实了ξ(2230)的存在,并首次发现ξ(2230)的非奇异衰变模式.测量了f0(980)、f2(1270)的共振参数和极化.对J/ψ→K+K-过程短分析的结果表明fJ(1710)是含有0++和2++两个态的宽结构.采用分波法测定了η(1440)、f0(1500)的自旋宇称,得到它们的主要衰变模式. 相似文献
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通过对J/ψ辐射衰变到K+K-π0和K0SK±π+终态中iota能区的振幅分析,发现iota峰下有一个0-+共振态(M=1467±3MeV,Γ=89±6MeV)和两个1++共振态(M=1435±3MeV,Γ=59±5MeV; M=1497±2MeV,Γ=44±7MeV),分别对应于η(1440),f1(1420)和f1(1510). 相似文献
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本文通过对J/ψ辐射衰变到K+K-πO和K0SK±π+终态中iota能区的振幅分析,发现iota峰下有一个0-+共振态(M=1467±3MeV,Γ=89±6MeV)和两个1++共振态(M=1435±3MeV,Γ=59±5MeV;M=1497±2MeV,Γ=44±7MeV),分别对应于η(1440),f1(1420)和f1(1510). 相似文献
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利用工作在北京正负电子对撞机(BEPC)上的北京谱仪(BES)收集到的33pb-1的Ψ(3770)数据,寻找D介子味道改变中性流(FCNC)和轻子数不守恒(LNV)的稀有衰变, 包括4个D0介子的衰变模式(K0e+e-,Φe+e-,ρ0e+e-和K*0e+e-)和6个D+介子的衰变模式(K-e+e+,K+e+e-,π-e+e+, π+e+e-,K*-e+e+和K*+e+e-). 没有发现信号,给出90%置信水平的上限. 其中, D+介子的两个衰变模式D+→K*-e+e+和D+→K*+e+e-的上限是首次测量. 相似文献
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用推广的矩分析方法讨论了过程J/ψ→X+f0(980),X→K+K-,f0(980)→π+π-.利用得到的矩表达式,可以确定玻色共振态X的自旋-宇称. 相似文献
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FU Zi-Wen 《中国物理C(英文版)》2015,39(8):083101-083101
Using a conventional constituent-quark model,I=1/2 scalarκ,vector K*(892),and axial vector K1mesons are studied in the asqtad-improved staggered fermion with wall-source and point-sink interpolators.The mass ratio of mκ/mK*(892)is numerically confirmed to apparently vary with quark mass,and the experimental ordering mK*(892)mκholds elegantly when the light u/d quark masses are sufficiently small,while the valence strange quark mass is fixed to its physical value.We also get reasonable signals for the K1 meson suggested by the SCALAR Collaboration from lattice QCD.The computations are conducted with the MILC Nf=3 flavor gauge configurations at three lattice spacings:a≈0.15,0.12,and 0.09 fm. 相似文献
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P. V. Chliapnikov V. P. Falaleev L. N. Gerdyukov A. I. Kurnosenko V. N. Riadovikov A. M. Rybin G. I. Sorokin V. A. Uvarov A. P. Vorobjev E. A. De Wolf J. J. Dumont M. Van Immerseel F. Grard CERN-USSR Collaboration 《Zeitschrift fur Physik C Particles and Fields》1982,12(2):113-122
Results are presented on total and semiinclusive cross sections, longitudinal and transverse momentum distributions of the tensor mesonsK *+(1430),K *0(1430), andf(1270) observed inK + p interactions at 32 GeV/c. The data are compared withK *+(892).K *0(896) and ?0 vector meson production in the same experiment. The shapes of inclusive invariantx-spectra for the strange vector and tensor mesons are found to be rather similar, after removal of diffractive and quasi-two-body channels, in agreement with quark-recombination ideas. 相似文献
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K. Yamada 《Physics letters. [Part B]》1980,97(1):156-158
We discuss the precise momentum dependence of the Ke3 form factor f+(t) by studying some of the recent experimental results on K0L → π± e? ν decays. The parametrization of f+(t) based on the assumption of K1-dominance can considerably improve the agreement of Sirlin's relation with existing data. 相似文献
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M.S. Khan M.J. Aslam A.H.S. Gilani Riazuddin 《The European Physical Journal C - Particles and Fields》2007,49(3):665-674
Form factors parameterizing radiative leptonic decays of heavy mesons (B+→γl+νl) against photon energy are computed in the language of dispersion relations. The states contributing to the absorptive part
in the dispersion relation are the multiparticle continuum, estimated by the quark triangle graph, and resonances with quantum
numbers 1- and 1+, which includes B* and BA
* and their radial excitations, which model the higher state contributions. Constraints provided by the asymptotic behavior
of the structure dependent amplitude, Ward identities and gauge invariance are used to provide useful information for the
parameters needed. The couplings gBB*γ and fBBA*γ are predicted as we restrict ourselves to the first radial excitation; otherwise using these as an input the radiative decay
coupling constants for the radial excitations are predicted. The value of the branching ratio for the process B+→γμ+νμ is found to be in the range 0.5×10-6. A detailed comparison is given with other approaches. 相似文献
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N. M. Agababyan I. V. Ajinenko Yu. A. Belokopytov H. Boettcher P. V. Chliapnikov F. Crijns A. De Roeck E. A. De Wolf K. Dziunikowska Z. C. Garutchava V. G. Gavrjusev H. Graessler G. R. Gulkanyan P. van Hal T. Haupt W. Kittel D. Kisielewska F. Meijers A. B. Michalowska V. I. Nikolaenko L. C. S. Oliveira K. Olkiewicz V. M. Ronjin A. M. Rybin H. M. T. Saarikko Y. T. M. Saarikko W. Schmitz L. Scholten O. G. Tchikilev L. A. Tikhonova A. G. Tomaradze V. A. Uvarov F. Verbeure R. Wischnewski A. Wróblewski S. A. Zotkin EHS-NA Collaboration 《Zeitschrift fur Physik C Particles and Fields》1989,41(4):539-555
A detailed analysis of the inclusive production of the vector mesonsφ,K *+,0(892) \(\bar K*^0 (892),\rho ^{ + ,0} ,\omega \) and the tensor mesonsK 2 *0 )(1430) andf 2(1270) inK + p interactions at 250 GeV/c is presented The data are compared with results at lower energies and with various quark-parton models. The production ofρ 0,K *0(892) and \(\bar K*^0 (892)\) increases at the same rate as a function ofs, is concentrated in the central region and is not reproduced by the models. Production of the tensor mesonsf 2(1270) andK 2 *0 (1340) is suppressed relative toρ 0 andK *0(892) by a factor of about 3. 相似文献
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A simple idea about quark-quark or quark-diquark reaction mechanism is proposed to predict thex F spectra in \(\bar p\) p interactions. Over a wide energy range, it is applied to the strange particle production in \(\bar p\) interactions and found that it reproduces well thex F spectra of strange particleK s 0 ,K *± ,Ε 0 andΣ +(1385) productions, especially, including the leading effect in the case of strange baryonΕ 0,Σ +(1385) productions. 相似文献
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本文求出了Eliashberg方程在T=Tc时的解,得到了下面的临界温度级数表示式:Tc=α0(μ*)(λ〈ω2〉)1/2{1+1/λα1(μ*)〈ω4>/〈ω2>2+1/λ2(α21(μ*)〈ω6>/〈ω2>3+α22(μ*)〈ω4>2/〈ω2>4) +1/λ3(α31(μ*)〈ω8>/〈ω2>4+α32(μ*)(〈ω4>〈ω6>)/〈ω2>5)+α33(μ*)〈ω4>3/〈ω2>6+…},其中α0(μ*),α1(μ*)等仅是μ*的函数。新的Tc公式表明了,Tc不仅依赖于λ、μ*和〈ω2〉,而且依赖于有效声子谱α2F(ω)的各级矩〈ω2n〉。 相似文献
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We perform a dispersion relation type calculation of the I = 0 S-wave amplitude g0+ (t) for the process , in the region from t = 4μ2 to t = (1100 MeV)2. Crossing is imposed by generalizing the newly developed hyperbolic partial-wave relations to our reaction and by imposing them on our amplitude using experimental Kπ phase-shift information as input. Analyticity and unitarity is imposed by generalizing the formalism of BFP [1] for parametrizing partial-wave amplitudes. This readily allows us to impose the experimental cross section. Finally the low energy behaviour is constrained to lie within certain limits recently deduced from fixed-tKπ dispersion relation studies [2] and including the current algebra prediction as a special case. We are able to resolve a previous controversy regarding the sign of Im g0(+) (t). 相似文献