The $\Lambda_b\to J/\psi+\Lambda$ Decay Revisited
Abstract
The $\b$ decay does not receive any nonspectator contributions and hence its theoretical calculation is relatively clean. Two different methods are employed for the study of $\b$. In the first method, both $b$ and $s$ quarks are treated as heavy and leading $1/m_s$ as well as $1/m_b$ corrections are included. The branching ratio and the asymmetry parameter $\alpha$ are found to be $(0.71.5)\times 10^{3}$ and $0.18$, respectively. In the second method, only the $b$ quark is treated as heavy. The prediction of the decay rate is very sensitive to the choice of the $q^2$ dependence for form factors. We obtain $\alpha=0.31$ and ${\cal B}(\b) \simeq 1.6\times 10^{4}$ for dipole $q^2$ behavior as well as $8.2\times 10^{4}$ for monopole $q^2$ dependence. We conclude that ${\cal B}(\b)~{\large ^<_{\sim}}~10^{3}$ and $\alpha$ is of order $0.20\sim 0.30$ with a positive sign.
 Publication:

arXiv eprints
 Pub Date:
 November 1994
 arXiv:
 arXiv:hepph/9411215
 Bibcode:
 1994hep.ph...11215C
 Keywords:

 High Energy Physics  Phenomenology
 EPrint:
 7 pages