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本文讨论了双荷子系统的能谱, 表明双荷子系统哈密顿量HD=1/2M π2-α/r+μ2/2Mr2具有SO(4)对称性. 相似文献
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本文从超对称性破缺的角度讨论了位于典型U(3)限区域的奇A核63Eu153, 在能谱和B(E2)方面得到了一些定量符合的结果. 相似文献
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本文提出了一个对称性破缺前不仅左、右对称, 而且中微子(或反中微子)与荷电轻子、反轻子的弱作用也相同的SU(3)×U(1)模型. 这一模型无三角反常; 导出了sin2θw≤1/4; 在低能范围内与标准模型一致. 我们反轻子数推广为轻子荷. 证明了只有轻子荷才是严格守恒的, 各代轻子数分别守恒只能近似成立. 夸克不仅带有重子数、电荷, 而且也带有轻子荷. 本模型预言有μR→eR+νeL+νμR, e-+e-→μ-+μ-等现象. 相似文献
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我们用粒子鉴别系统测量了31.2MeV的α粒子在11,10B核上的(α,t)、(α,d)和(α,p)反应的角分布; 由出射粒子的能谱, 我们分别得到了剩余核处于基态和不同激发态的十个角分布. 从角分布的形状看, 在11B(α,t0)12Cg﹒s, 11B(α,d0)13Cg﹒s, 10B(α,d0)12Cg﹒s, 10B(α,d1)12C1st, 11B(α,p0)14Cg﹒s等反应中均有不同程度的后角上翘; 并且(α,t0)和(α,p0)的后角上翘的同位素效应似乎与(α, α)的反常散射的同位素效应相反. 相似文献
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本文内容包括:(ⅰ)进一步给出SU(2)×U(1)×S3模型的结果S2≈S3≈(ms2)/(mb2);sin δ≤(mumd)/(mcms),并预言b夸克的主要衰变道是b→u+W,b夸克的寿命可能长到10-9秒.(ⅱ)给出类K0-K0系统混合时的精确表达式ρ=错号事例数/对号事例数=(1/2)(|p/q|2+|q/p|2)([Γ2+(Δm)2]2-(γ1γ2)2)/([Γ2+(Δm)2]2+(γ1γ2)2);并给出CP破坏的精确表达式:A=(1-ρ')/(1+ρ')=(IM12Γ12*)/(|M12|2+1/4|Γ12|2),这里ρ′=(负电错号事例数)/(正电错号事例数)。 相似文献
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Some authors consider the ψ(4415) to be the 4S or 5S excited tate of a cc pair. Starting from this assumption, we study he decays of the ψ(4415) to DD, D*D*, DSDS, DS*DS*, and get the corresponding branching ratios in terms of the Quark-Pair-Creation (QPC) model. Compared with the experimental data, we find that the results of 4S state agree much better than those of the 5S state. Therefore, it is more reasonable to assume the ψ(4415) to be a 4S state. 相似文献
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Wave function is important for determining decay constants fDS- and fD-. Using the 5 types of D meson wave functions in the heavy quark limit, we studied the uncertainties of radiative pure-leptonic decays of DS-(D-) mesons. The branching ratios are (1.025390—1.706812) × 10-5 and (0.953498—1.576725) × 10-6 for DS- and D- decays, respectively, which are sensitive to the type of wave function. 相似文献
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The Babar Collaboration announced two new excited charmed baryons Ξc(3055)+ and Ξc(3123)+. We study their strong decays assuming they are D-wave states. Some assignments are excluded by comparing our numerical results with the experimental values of the total widths of Ξc(3055)+ and Ξc(3123)+. We also suggest some possible decay modes, which will be helpful to 相似文献
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Apart from the charmful decay channels of Y(4260), the charmless decay channels of Y(4260) also provide us a good platform to study the nature and the decay mechanism of Y(4260). In this paper, we propose to probe the structure of Y(4260) through the charmless decays Y(4260)→VP via intermediate D1D+c.c. meson loops, where V and P stand for light vector and pseudoscalar mesons, respectively. Under the molecule ansatz of Y(4260), the predicted total branching ratio BRVP for all Y(4260)→VP processes are about (0.34-0.23+0.23)% to (0.75-0.52+0.72)% with the cutoff parameter α=2-3. Numerical results show that the intermediate m D1D+c.c. meson loops may be a possible transition mechanism in the Y(4260)→VP decays. These predicted branching ratios are the same order to that of Y(4260)→Zc+(3900)π-, which may be an evidence of D1D molecule and can be examined by the forthcoming BESⅢ data in the near future. 相似文献
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Based on the assumption that Ds1(2536) and Ds2(2573) belong to T doublet (1+,2+), we calculate the semileptonic decays of Bs to Ds1(2536) and Ds2(2573) in terms of the Constituent Quark Meson (CQM) model. For Bs→Ds1(2536)+lν and Bs→Ds2(2573)+lν, the order of magnitude of the obtained branching ratios is 10-3. Our numerical results of the semileptonic decays of Bs to Ds1(2536) and Ds2(2573) are large, which implies that two semileptonic decays should be seen 相似文献
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用生态坐标方法(GCM)[1]a考虑集体3-态与非集体粒子空穴对(ph)l+耦合模型计算了铅(208)3-集体态的电四极知Q[3-]、电八极约化跃迁几率B(E3)和跃迁密度ρtr3-随核的径向距离r的变化曲线. 结果是:Q[3-]=-0.098eb1),B(E3)=38w.u.2). 计算中没有像通常那样假设一个有效核子电荷而是在GCM框架下考虑核心激发进行微观计算, 其结果与实验符合, 说明GCM能够对核元激发的耦合作微观研究. 相似文献
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应用格林函数方法本文较仔细地研究了单粒位阱的非厄米选择uαβ=Mαβ(εβ)[或Mαβ(εα)],其中Mαβ(ω)=Mαβon(ω)+Mαβoff(ω)表示质量算符.文中从另一个角度给出了Mαβon(ω)与Mαβoff(ω)的定义并指出,质量算符插图可以分为三类项之和: (1)由Mαβoff(ω)的极点贡献的项.这类项不可分离,只有它们需要另行处理; (2)可以由上述非厄米选择完全抵销的项,这提供了选择uαβ的一个依据; (3)剩余项.这部分项可以简单地求和并且可以解释为单粒格林函数的振幅修正. 作为应用举例,文中讨论了粒子-空穴格林函数的重整化无规位相近似(RRPA),给出了有关的计算公式.在RRPA中不仅顾及了G矩阵的偏离能壳性,而且还计及了单粒传播子的重整化,后者除Mαβoff(ω)所含极点的贡献外考虑了所有其它效应. 相似文献
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In this paper we study the semileptonic decays of Bc-→(ηc,J/Ψ)l-vl. We first evaluate the Bc→(ηc,J/Ψ) transition form factors F0(q2), F+(q2), V(q2) and A0,1,2(q2) by employing the pQCD factorization approach, and then we calculate the branching ratios for all considered semileptonic decays. Based on the numerical results and the phenomenological analysis, we find that: (a) the pQCD predictions for the values of the Bc→ηc and Bc→J/Ψ transition form factors agree well with those obtained by using other methods; (b) the pQCD predictions for the branching ratios of the considered decays are Br(Bc-→ηc e-ve(μ-vμ)=(4.41-1.09+1.22)×10-3, Br(Bc-→ηcτ-vτ) =(1.37-0.34+0.37)×10-3, Br(Bc-→J/Ψ e-ve(μ-vμ)) =(10.03-1.18+1.33)×10-3, and Br(Bc-→J/Ψτ-vτ) =(2.92-0.34+0.40)×10-3; and (c) we also define and calculate two ratios of the branching ratios Rηc and RJ/Ψ, which will be tested by LHCb and the forthcoming Super-B experiments. 相似文献
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Belle Collaboration reported a new observed value of K*-(892) mass by studying τ-→ KSπ-ντ decay, which is significantly different from the current world average value given by Particle Data Group 2006. Motivated by this new data, we revisit the issue on the K*0(892)-K*±(892) mass splitting. Our theoretical estimation favors the new measurement by Belle Collaboration. Therefore further experimental efforts are urgently needed to improve our understanding of these issues. 相似文献
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实验证据分析表明: 大变形区的核电荷方均根半径常数rp无例外地比相邻球形核大一些. 这可以用形变效应来说明. 中子数在下列壳层中1p3/2(N~3—6), 1d5/2(N~9—14), 1f7/2(N~20—28), 1g9/2(N~40—50), 1h11/2(N~70—82)的各同位素的电荷半径的变化(随A的增大半径反而变小等)与A1/3律完全抵触. 在Z1/3律基础上, 考虑形变效应后可给予较好的说明. 相似文献