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基于螺旋度分波分析公式 ,我们探讨在J ψ→fJ(θ1,1)、fJ→ππ(θ2 ,2 )、→K+ K-(θ3 ,3 )级联衰变过程中是否可以通过各种一维角分布投影鉴别出f0 和f2 共振态 .结果表明 ,f0 和f2 可以同时给出完全相同的 (θ1,1,θ2 ,2 )一维投影 ,但不能同时给出完全相同的 (θ1,1,θ2 ,2 ,3 )一维投影 .因此 ,要想保证从角分布的一维投影鉴别出f0 和f2 ,必须同时考虑所有三个衰变顶角的角分布信息 . 相似文献
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用BESⅠ的 7.8× 1 0 6 J/ ψ数据更为精确地测定了J/ ψ→π0 3 (π+π- )和J/ ψ→ω2 (π+π- )的分支比 (Br(J/ ψ→π0 3 (π+π- ) ) =( 2 .52± 0 .0 6± 0 .4 3 ) % ,Br(J/ ψ→ω2 (π+π- ) ) =( 1 .3 1± 0 .0 9± 0 .2 1 ) % .同时对 4π不变质量谱和ωππ不变质量谱进行研究分析 ,试图观察是否存在有兴趣的信号 . 相似文献
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利用推广的矩分析和双态耦合处理方法,给出了双态耦合情况下J/ψ衰变过程J/ψ→ρρπ的矩表达式,为在J/ψ衰变过程中寻找并确定1-+奇特态的性质提供了一种可能的途径. 相似文献
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基于螺旋度分波分析公式,我们探讨在J ψ→fJ(θ1,1)、fJ→ππ(θ2 ,2 )、→K+ K-(θ3 ,3 )级联衰变过程中是否可以通过各种一维角分布投影鉴别出f0 和f2 共振态.结果表明,f0 和f2 可以同时给出完全相同的(θ1,1,θ2 ,2 )一维投影,但不能同时给出完全相同的(θ1,1,θ2 ,2 ,3 )一维投影.因此,要想保证从角分布的一维投影鉴别出f0 和f2 ,必须同时考虑所有三个衰变顶角的角分布信息. 相似文献
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用BESⅠ的7.8×106J/ψ数据更为精确地测定了J/ψ→π03(π+π-)和J/ψ→ω2(π+π-)的分支比(Br(J/ψ→π03(π+π-))=(2.52±0.06±0.43)%,Br(J/ψ→π03(π+π-))=(1.31±0.09±0.21)%.同时对4π不变质量谱和ωππ不变质量谱进行研究分析,试图观察是否存在有兴趣的信号. 相似文献
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基于J/ψ辐射产生胶球态Gb和湮没为e+ē对两过程的中间态和末态都不涉及任何夸克强子而只与强作用的真空性质密切相关这一特性,从另一种角度讨论了这两个过程.利用高能强作用软过程中修改后的pomeron场论模型和相关的最大非微扰强作用反应假定,并考虑到轻的和重的组分夸克在结构上的差异而在模型参数中作出相应的变更后,提出了这两个过程的另一种物理机制,计算了它们的衰变宽度,定出了胶球态与非微扰胶子间的耦合数值,并就此进行了简单的讨论.
关键词:
J/ψ衰变
pomeron
非微扰 相似文献
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Q值的影响因素分析及其参数化 总被引:1,自引:1,他引:0
针对高散射特性的二类水体中难以测量的双向性函数Q,利用HYDROLIGHT模拟观测角为太阳天底角下440 nm处的Q值,并分析环境及水体光学特性对Q值的影响.结果表明,在高散射特性的近岸水体或内陆湖泊水体中,由于散射次数的增加,使得风速、散射相函数等影响因素对Q值影响相对减小,单次散射反照率W.和太阳天顶角θ成为Q值的主要影响因素;随着深度的增加,双向性函数Q受边界条件和光线入射状况影响的程度逐渐减少,直至不受其影响,而成为只与固有光学量相关的内秉光学量;利用Q值的主要影响因素W<,0>、θ和上行辐亮度的漫衰减系数K<,L<,u>>分别对Q值进行参数化,得到Q值的2种参数表达式. 相似文献
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Shenggen Yao Mark G. Hinds Raymond S. Norton 《Journal of magnetic resonance (San Diego, Calif. : 1997)》1998,131(2):347-350
In the study of protein backbone dynamics by15N relaxation measurements, an initial estimation of the isotropic global correlation time, τm, is usually obtained from the averageT1/T2ratio of nuclear spins that do not exhibit slow internal motion and withT2values not significantly shortened by chemical or conformational exchange processes. Different methods have been used for identification of the rates of internal motion. However, the number of nuclear spins included in the τmestimation is often larger than the number that ultimately can be fitted to a single-order parameter,S2, implying that some nuclear spins involved in the initial τmestimation actually have an effective internal correlation time, τe, not as fast as assumed. As a consequence, τmis underestimated, since internal motion reduces theT1/T2ratio. This situation becomes more obvious if the molecule has a large τmvalue because the reduction inT1/T2ratio arising from internal motion is more significant than for molecules with smaller τmand the same degree of internal motion. This Communication describes a more reliable method for identifying nuclear spins which should be excluded from the τmestimation because of insufficiently rapid internal motion. This results in an improved τmvalue, giving a much better agreement between the number of nuclear spins fitted successfully to a single-order parameter,S2, and those used in the τmestimation. 相似文献
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It is well known that an inverse problem of biomagnetic imaging is generally ill-posed. Recently several attempts using biocoherence have been reported, but the ill-condition is not considered in these previous methods. If the conventional reconstruction formula is under the ill-condition, the reconstruction problem is also ill-posed and the ill-posedness cannot be improved. In this paper, we propose an approach to estimate the location of current sources under the condition that sources of different positions have little or weak correlation. Our method is based on a well-known regularization method, the truncated SVD method. Compared with the conventional method, our technique allows accurate determination of the location of current sources because it improves the ill-posedness of the inverse problem. We carried out computer simulations using the half-space conducting model and confirmed the effectiveness of our method. 相似文献
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对多边形单元上平均值插值的误差进行分析,利用平均值插值形函数的性质和二元函数的Taylor展开式,证明平均值插值的误差估计不等式.给出平均值插值应用于凸域温度分布插值近似的算例,数值算例表明平均值插值能够表现出区域温度分布的特征. 相似文献
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We particularize criteria proposed by one of the authors for estimating the probability densities of a random vector of size
N to the case of even N. For the presentation convenience in this case, two-dimensional vectors are treated as complex random
variables and the probability densities of their absolute values and arguments are estimated. The estimation algorithms are
synthesized on the basis of the obtained criteria under conditions of both presence and absence of complete a priori information
on the sample statistic. A number of examples are given to prove that the obtained algorithms are optimal in the statistical
sense.
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Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 48, No. 7, pp. 616–627, July 2005. 相似文献
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Statistically perturbed angular correlations of160Dy and172Yb have been time differentially investigated in liquid sources. As solvents we used ethylalcohol and concentrated hydrochloric acid at various temperatures. From our results we have calculated the ratio of the spectroscopic quadrupole moments of the 2+ rotational and the 3+ isomeric level in172Yb asQ 3+/Q 2+=1.33±0.14. 相似文献
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Without the non-relativistic approximation in one-loop function, the dominating one-loop con-tribution to the quark-antiquark potential is studied numerically in terms of perturbative Quantum Chromo Dynamics (QCD). For Coulomb-like potential, the ratio of the one-loop correction to the tree diagram con-tribution is presented, whose absolute value is about 20%. Our result is consistent with the analysis that the one-loop contribution should be suppressed by a factor αs/π to the leading order contribution. This work can deepen the comprehension of αs in Cornel potential. 相似文献
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Investigations in a periodically driven neon glow discharge show that the occurrence of bestabilities can lead to chaotic states. These states are caused by wave phenomena. Characterizing this behaviour by means of the autocorrelation and the crosscorrelation function without the knowledge of the power spectra can imply false interpretations. These are due to the different dissipation of the fluctuations synchronous with the phase-shifted excitation. It is demonstrated that much information obtained from a large set of data is needed for a reliable evaluation of the dynamics of chaotic states. 相似文献