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arXiv 0904.4375hep-ph
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$B$介子衰变为两个费米子的一般分析

General Analysis of $B$ Meson Decay into Two Fermions

Akihiro Matsuzaki

摘要:

研究了如何用模型无关的方法测量$B$介子衰变为两个不稳定费米子$\bar f_a$和$f_b$过程的电流结构。我们使用受$\bar f_a f_b$自旋关联影响的后续衰变产物的动量分布。我们发现以下情况:(1)由$\bar f_a$和$f_b$衰变粒子间的张角可求出两个有效耦合常数的绝对值;(2)由$\bar f_a$或$f_b$衰变粒子的能量分布可求出干涉的实部。(3)从$\bar f_a$和$f_b$的两个衰变粒子的能量分布中无法获得新的信息。(4)干涉的虚部是从末态衰变产物的方位角不对称性中提取的。(5)如果两个费米子中只有一个是不稳定的,我们可以从每个能量分布和张角分布中提取干涉的实部。我们展示几个简单的例子。

英文摘要:

We study how to measure the current structure of the process that $B$ meson decays into two unstable fermions $\bar f_a$ and $f_b$ in model independent way. We use the momentum distributions of subsequent decay products affected by $\bar f_a f_b$ spin correlation. We have found the following: (1) We can extract the absolute values of two effective coupling constants from the opening angle between the particles decayed from $\bar f_a$ and $f_b$ (2) We can extract the real part of the interference from the energy distribution of one of the decayed particles from $\bar f_a$ or $f_b$. (3) No new information can be obtained from the energy distribution of two decayed particles from $\bar f_a$ and $f_b$. (4) The imaginary part of interference is extracted from the azimuthal angle asymmetry of final-state decay products. (5) If only one of two fermions is unstable, we can extract the real part of interference from each of the energy distribution and opening angle distribution. We show several simple examples.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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