Hadronic Weak Decays of Λb Baryon in the Covariant Oscillator Quark Model
Hadronic Weak Decays of Λb Baryon in the Covariant Oscillator Quark Model
复制标题
协变振子夸克模型中Λb重子的强子弱衰变
DOI：
10.1143/ptp.101.959
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发表时间：
1999
影响因子：
--
通讯作者：
M. Oda
中科院分区：
文献类型：
--
作者：
R. Mohanta;A. Giri;M. P. Khanna;M. Ishida;S. Ishida;M. Oda
在因子化近似下，分析了Cabibbo允许的ΛB重子的两体弱衰变.我们用协变振子夸克模型计算了重→重和重→轻的形状因子。当应用于重夸克极限时，我们的形状因子满足重夸克对称性所施加的所有约束。计算了ΛB重子衰变到Λc + P（V）的衰变率和上下不对称性.结果表明，在所有这些衰变模式中，上下不对称性都是负的。此外，Br（ΛB → Λ + J/J）= 2.49 × 10 −4的预言与最近的实验数据一致.最后指出，CKM-Wolfenstein参数ρ 2 + η 2（其中η为CP相）可由宽度Λb → Λ <$D0与宽度ΛB → ΛJ/λ的比值确定，而与QCD参数无关。用我们的模型计算的（ρ 2 + η 2）1/2值与Rosner最近预测的值非常吻合。
Cabibbo allowed two-body hadronic weak decays of Λb baryons are analyzed in the factorization approximation. We use the covariant oscillator quark model to evaluate the heavy → heavy and heavy → light form factors. When applied in the heavy quark limit, our form factors satisfy all the constraints imposed by heavy quark symmetry. The decay rates and up-down asymmetries for Λb baryon decaying into Λc + P (V ) are calculated. It is found that the up-down asymmetry is negative in all these decay modes. Furthermore, the prediction Br(Λb → Λ + J/ψ )=2 .49 × 10 −4 is consistent with the recent experimental data. Finally it is pointed out that the CKM-Wolfenstein parameter ρ 2 + η 2 , where η is the CP phase, can be determined from the ratio of the widths Λb → Λ ¯ D 0 and Λb → ΛJ/ψ, independent of the QCD parameter. The value of (ρ 2 + η 2 ) 1/2 calculated in our model agrees very well with the value recently predicted by Rosner.